Christians often give lip-service to the idea of "walking in/by the Spirit" and "living by the power of the Spirit," but practically what they do is act by the powers of their flesh: force of will, intellect, physical strength. Because these powers are bent toward "godly" things - Christian ministry, Bible study, moral living, etc. - they believe they're "walking in/by the Spirit," that they are being "godly." But what they are really doing is trying to achieve a godly end by means of their flesh. In other words, they're not being spiritual but fleshly, or carnal. It doesn't look bad, though, when a Christian does this, when they use the wrong "power source" to walk with God. And so, most Christians live as such, perhaps for their entire lives, thinking all the while that they are pleasing to God when, in fact, they are doing precisely what He warned them NOT to do: walk in the flesh.
Galatians 6:7-8
7 Be not deceived; God is not mocked: for whatever a man sows, that shall he also reap.
8 For he who sows to his flesh shall of the flesh reap corruption; but he who sows to the Spirit shall of the Spirit reap life everlasting.
Romans 8:5-8
5 For those who are according to the flesh set their minds on the things of the flesh, but those who are according to the Spirit, the things of the Spirit.
6 For the mind set on the flesh is death, but the mind set on the Spirit is life and peace,
7 because the mind set on the flesh is hostile toward God; for it does not subject itself to the law of God, for it is not even able to do so,
8 and those who are in the flesh cannot please God.
Galatians 5:17
17 For the flesh sets its desire against the Spirit, and the Spirit against the flesh; for these are in opposition to one another, so that you may not do the things that you please.
Every day, a Christian walks either in/by the Spirit of they walk in/by their flesh. There aren't any other options. And a Christian who may at one point in a day be truly walking in/by the Spirit may at another point have migrated into walking in/by the flesh. How can they know when they have? By what criteria can they tell that they have left off walking in/by the Spirit and are now walking in the flesh (godly though their doing so may appear to be)? The vast majority of Christians I've encountered through my fifty years of walking with God have no idea. And so, they are mostly walking in/by their flesh but thinking they're walking in/by the Spirit.
There are "tells," however, clear indicators, that a believer is operating by means of fleshly power rather than by the power of the Spirit.
1.) The "fruit" of the flesh.
A believer who is living by means of their own human powers - force of will, intellect, physical strength - inevitably produces a "harvest" of fleshliness, though it is usually "spiritualized." For example, there's a born-again man who has, for decades, labored to maintain the physical premises in which a community of Christians meet, mowing the lawn, fixing the plumbing, repairing deteriorating sidewalks or steps, etc. He's not being paid to do so, but in service to God, has made the effort and sacrifices of time and energy that he has to keep the church building and grounds in good condition.
But he has come resent that no one seems to notice his work; no one has applauded him, thanked him, or made a bit of appreciative noise about his labors. And as he gets older and the work is more difficult to do, he resents even more deeply that his work has gone unnoticed, folks taking for granted that he will always do as he's done for the church.
Slowly, but surely, the fleshliness at the root of this man's work poisons what he's been doing, making an act, ostensibly of worship, love and service to God, the source of deep bitterness and frustration instead. Were he serving in the Spirit's power, the fruit of the Spirit would fill his heart and actions, giving him joy in his labor, the opportunity to serve God by serving the church more than sufficient reward.
This is always how the flesh exposes itself when it is employed in Christian living. Spiritualized though it may be, fleshly effort produces resentment, a quickness to take offense, temper, divisiveness, and pride. See Galatians 5:19-21; James 3:13-18; 1 Corinthians 3:1-3, etc. . As well, when one's flesh is the power source for living, this fact manifests in severe, chronic depression, acute anxiety, various neuroses, addictive behaviours - all those things opposite, or contrary, to the fruit of the Spirit: Love, joy peace, patience, gentleness, goodness, faith, meekness and self-control (Galatians 5:22-23; Ephesians 5:9).
2.) Exhaustion (of enthusiasm and joy for the life and work of Christian living).
When a Christian is operating from the power of their flesh rather than the power of the Spirit, they grow "weary in well-doing," exhausted by the effort of being holy, wrung out by keeping the "lid" on the "pot" of ungodly desires constantly "on the boil" within them, finally collapsing into moral and spiritual compromise when their finite fleshly resources are depleted.
In contrast, the believer walking in/by the power of the Spirit has exactly the opposite experience:
Isaiah 40:28-31
28 Do you not know? Have you not heard? The Everlasting God, the LORD, the Creator of the ends of the earth Does not become weary or tired. His understanding is inscrutable.
29 He gives strength to the weary, And to him who lacks might He increases power.
30 Though youths grow weary and tired, And vigorous young men stumble badly,
31 Yet those who wait for the LORD Will gain new strength; They will mount up with wings like eagles, They will run and not get tired, They will walk and not become weary.
Psalm 84:5-7
5 Blessed is the man whose strength is in you; in whose heart are the ways of them.
6 Who passing through the valley of Baca make it a well; the rain also fills the pools.
7 They go from strength to strength...
Philippians 4:13
13 I can do all things through Christ which strengthens me.
John 7:38-39
38 "He who believes in Me, as the Scripture said, 'From his innermost being will flow rivers of living water.'"
39 But this He spoke of the Spirit, whom those who believed in Him were to receive...
3.) No increased knowledge or experience of God.
At the end of a season of labor for God, done in God's power, the believer always has more knowledge of God, more experience of Him. But the believer who is operating according to fleshly power and in fleshly ways, has only greater knowledge of themselves, of their fleshly abilities, and of the ways of the flesh.
For example, let's say the foundation of a church building is in need of significant repairs. The leadership of the church respond by "praying about it," in so doing sanctifying an entirely fleshly, worldly process of repair, relying on aggressive fund-raising and bank loans to cover costs of repair. At every step of the way, the repairs to the church foundation are spiritualized by prayer and statements of praise to God for working through the aggressive fund-raising and bank loans to accomplish repairs. But many non-Christian organizations needing similar repairs to physical infrastructure have done exactly the same thing and met with exactly the same success. Apart from spiritualizing proclamations on the part of the Christians, there is no difference between the worldly way and the "Christian" way of effecting repairs.
What, then, have the Christians learned about God in the process of the church repairs? Nothing - though they claim that it's all been by His doing that the foundation was fixed. No, all the Christians actually learned in the matter of the foundation repair was how to do aggressive fund-raising and obtain a bank loan. God has not actually done anything to overtly mark His participation in the repair and, in fact, was never given a chance to do so.
What if God had not wanted the repairs to be done? What if God had used a withholding of His supernatural supply for the repair of the church building to expose the sinfulness and carnality of the believers meeting within it? What if God had wanted the believers meeting in the building to move to other premises entirely? None of these possibilities were permitted by the church leadership to unfold, despite their spiritualizing claims. It was, for them, a foregone conclusion - and a very fleshly one - that the church building would be fixed, even though it was going to cost millions of dollars to do so.
At the end of the process of repairs, the Christians in the church community were eager to give praise to God for what He'd done. But what had He done, really? How was the entirely worldly character of the process of repair distinguishable from that of a secular institution doing the same? In this absence of the clear involvement of God in Christian living, the flesh may always be discerned. Oh, the Christians could point to their spiritualizing of the whole business, their prayers and praise of God, but on God's side of things there was a total vacuum of His supernatural leading and provision for the repair.
Continued below.
Galatians 6:7-8
7 Be not deceived; God is not mocked: for whatever a man sows, that shall he also reap.
8 For he who sows to his flesh shall of the flesh reap corruption; but he who sows to the Spirit shall of the Spirit reap life everlasting.
Romans 8:5-8
5 For those who are according to the flesh set their minds on the things of the flesh, but those who are according to the Spirit, the things of the Spirit.
6 For the mind set on the flesh is death, but the mind set on the Spirit is life and peace,
7 because the mind set on the flesh is hostile toward God; for it does not subject itself to the law of God, for it is not even able to do so,
8 and those who are in the flesh cannot please God.
Galatians 5:17
17 For the flesh sets its desire against the Spirit, and the Spirit against the flesh; for these are in opposition to one another, so that you may not do the things that you please.
Every day, a Christian walks either in/by the Spirit of they walk in/by their flesh. There aren't any other options. And a Christian who may at one point in a day be truly walking in/by the Spirit may at another point have migrated into walking in/by the flesh. How can they know when they have? By what criteria can they tell that they have left off walking in/by the Spirit and are now walking in the flesh (godly though their doing so may appear to be)? The vast majority of Christians I've encountered through my fifty years of walking with God have no idea. And so, they are mostly walking in/by their flesh but thinking they're walking in/by the Spirit.
There are "tells," however, clear indicators, that a believer is operating by means of fleshly power rather than by the power of the Spirit.
1.) The "fruit" of the flesh.
A believer who is living by means of their own human powers - force of will, intellect, physical strength - inevitably produces a "harvest" of fleshliness, though it is usually "spiritualized." For example, there's a born-again man who has, for decades, labored to maintain the physical premises in which a community of Christians meet, mowing the lawn, fixing the plumbing, repairing deteriorating sidewalks or steps, etc. He's not being paid to do so, but in service to God, has made the effort and sacrifices of time and energy that he has to keep the church building and grounds in good condition.
But he has come resent that no one seems to notice his work; no one has applauded him, thanked him, or made a bit of appreciative noise about his labors. And as he gets older and the work is more difficult to do, he resents even more deeply that his work has gone unnoticed, folks taking for granted that he will always do as he's done for the church.
Slowly, but surely, the fleshliness at the root of this man's work poisons what he's been doing, making an act, ostensibly of worship, love and service to God, the source of deep bitterness and frustration instead. Were he serving in the Spirit's power, the fruit of the Spirit would fill his heart and actions, giving him joy in his labor, the opportunity to serve God by serving the church more than sufficient reward.
This is always how the flesh exposes itself when it is employed in Christian living. Spiritualized though it may be, fleshly effort produces resentment, a quickness to take offense, temper, divisiveness, and pride. See Galatians 5:19-21; James 3:13-18; 1 Corinthians 3:1-3, etc. . As well, when one's flesh is the power source for living, this fact manifests in severe, chronic depression, acute anxiety, various neuroses, addictive behaviours - all those things opposite, or contrary, to the fruit of the Spirit: Love, joy peace, patience, gentleness, goodness, faith, meekness and self-control (Galatians 5:22-23; Ephesians 5:9).
2.) Exhaustion (of enthusiasm and joy for the life and work of Christian living).
When a Christian is operating from the power of their flesh rather than the power of the Spirit, they grow "weary in well-doing," exhausted by the effort of being holy, wrung out by keeping the "lid" on the "pot" of ungodly desires constantly "on the boil" within them, finally collapsing into moral and spiritual compromise when their finite fleshly resources are depleted.
In contrast, the believer walking in/by the power of the Spirit has exactly the opposite experience:
Isaiah 40:28-31
28 Do you not know? Have you not heard? The Everlasting God, the LORD, the Creator of the ends of the earth Does not become weary or tired. His understanding is inscrutable.
29 He gives strength to the weary, And to him who lacks might He increases power.
30 Though youths grow weary and tired, And vigorous young men stumble badly,
31 Yet those who wait for the LORD Will gain new strength; They will mount up with wings like eagles, They will run and not get tired, They will walk and not become weary.
Psalm 84:5-7
5 Blessed is the man whose strength is in you; in whose heart are the ways of them.
6 Who passing through the valley of Baca make it a well; the rain also fills the pools.
7 They go from strength to strength...
Philippians 4:13
13 I can do all things through Christ which strengthens me.
John 7:38-39
38 "He who believes in Me, as the Scripture said, 'From his innermost being will flow rivers of living water.'"
39 But this He spoke of the Spirit, whom those who believed in Him were to receive...
3.) No increased knowledge or experience of God.
At the end of a season of labor for God, done in God's power, the believer always has more knowledge of God, more experience of Him. But the believer who is operating according to fleshly power and in fleshly ways, has only greater knowledge of themselves, of their fleshly abilities, and of the ways of the flesh.
For example, let's say the foundation of a church building is in need of significant repairs. The leadership of the church respond by "praying about it," in so doing sanctifying an entirely fleshly, worldly process of repair, relying on aggressive fund-raising and bank loans to cover costs of repair. At every step of the way, the repairs to the church foundation are spiritualized by prayer and statements of praise to God for working through the aggressive fund-raising and bank loans to accomplish repairs. But many non-Christian organizations needing similar repairs to physical infrastructure have done exactly the same thing and met with exactly the same success. Apart from spiritualizing proclamations on the part of the Christians, there is no difference between the worldly way and the "Christian" way of effecting repairs.
What, then, have the Christians learned about God in the process of the church repairs? Nothing - though they claim that it's all been by His doing that the foundation was fixed. No, all the Christians actually learned in the matter of the foundation repair was how to do aggressive fund-raising and obtain a bank loan. God has not actually done anything to overtly mark His participation in the repair and, in fact, was never given a chance to do so.
What if God had not wanted the repairs to be done? What if God had used a withholding of His supernatural supply for the repair of the church building to expose the sinfulness and carnality of the believers meeting within it? What if God had wanted the believers meeting in the building to move to other premises entirely? None of these possibilities were permitted by the church leadership to unfold, despite their spiritualizing claims. It was, for them, a foregone conclusion - and a very fleshly one - that the church building would be fixed, even though it was going to cost millions of dollars to do so.
At the end of the process of repairs, the Christians in the church community were eager to give praise to God for what He'd done. But what had He done, really? How was the entirely worldly character of the process of repair distinguishable from that of a secular institution doing the same? In this absence of the clear involvement of God in Christian living, the flesh may always be discerned. Oh, the Christians could point to their spiritualizing of the whole business, their prayers and praise of God, but on God's side of things there was a total vacuum of His supernatural leading and provision for the repair.
Continued below.