For this is the love of God, that we keep His commandments. And His commandments are not burdensome.
1 John 5:3
Do you find it burdensome to keep His commandments?
Is it a huge burden for you to restrain yourself from committing adultery with your neighbors wife?
Is it burdensome for you to not lie?
No. Should it be? The love of God constrains me, and the power of the Holy Spirit enables me, so how can obeying God be a burden?
If anyone does not abide in Me, he is cast out as a branch and is withered; and they gather them and throw them into the fire, and they are burned. John 15:6
It seems you haven't considered that this verse may not say what you think it says. But this is what happens when one comes to the text of the Bible with a saved-and-lost perspective already in hand. Two alternative views on
John 15:6 are:
1.)
Verse 6 refers to a contrasting parallel figure to the "branch" in the "Vine": the lost person who is not in the Vine. Though a creature created by Christ - a branch - he is "cast out," in his unregenerate state spiritually detached from his Maker and thus made useless, good for nothing, like dead wood used for a fire.
John 15:4-5, then, describe the saved person and
verse 6 describes the unsaved person, not a saved person who
becomes a lost one.
2.)
Verse 6 refers, not to a believer who has lost his salvation, but merely to a believer who has ceased to be spiritually fruitful. The verse emphasizes
the uselessness of a branch that is supposed to be spiritually fruit-bearing but is not. Rather than the "throw them into the fire, and they are burned" referring to hell, the fitness of the branch only for fuel for a fire speaks to its total spiritual uselessness, as does
Ezekiel 15:1-6, to which Christ may be referring obliquely in
John 15:6.
Here is how we are instructed to remain “in Christ”.
Now
he who keeps His commandments abides in Him, and He in him. And by this we know that He abides in us, by the Spirit whom He has given us.
1 John 3:24
No, you are mistaking effect for cause, here. The
effect of abiding in Him (Christ) is obedience; the
means of abiding in Christ is not, however. What John is saying here is akin to someone saying, "He who drives a police car is a member of the police force." This is
not to say that driving a police car is
the means to being a member of the police force but merely
the effect, or consequence, of being such a member.
In actuality, it is the Holy Spirit who enables the believer to properly obey God. And this is why, in
1 John 3:24 (and in
1 John 4:13) the apostle John makes
the indwelling Spirit, not obedience, the means of knowing whether or not one is truly saved. There is no salvation apart from the Spirit of Christ, the Holy Spirit, coming to reside within a person. If he is not there, the person is still "dead in trespasses and sins."
Obedience, on the other hand, can be a pretense, the mask of the religious hypocrite, and a religious "club" these hypocrites often use to beat the flock of God. The Pharisees were of this sort, professionally obedient to God's law, known for their careful observance of His commands, even making a bunch of their own rules, too (as religious hypocrites usually do). But Jesus said their heart were far from God and that they were "sons of hell" and "white-washed tombs full of dead men's bones." No, obedience cannot be, then, the primary litmus test of genuine spiritual regeneration; the transforming work of the indwelling Holy Spirit is.
Philippians 2:13 (NASB)
13 for it is God who is at work in you, both to will and to work for His good pleasure.
2 Corinthians 3:18 (NASB)
18 But we all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as from the Lord, the Spirit.
Ephesians 3:16 (NASB)
16 that He would grant you, according to the riches of His glory, to be strengthened with power through His Spirit in the inner man,
Romans 8:13 (NASB)
13 for if you are living according to the flesh, you must die; but if by the Spirit you are putting to death the deeds of the body, you will live.
(See also:
John 16:8; 1 Corinthians 2:10-16; Galatians 5:22-23)