Hi Glory
Sometimes what we believe are good works are, in reality, self righteousness and sin. The works of our flesh is sin, no matter how good they may appear.
Paul gives an example here.
Philippians 3:3-10 For we are the circumcision, who worship God in the Spirit, rejoice in Christ Jesus, and have no confidence in the flesh, though I also might have confidence in the flesh. If anyone else thinks he may have confidence in the flesh, I more so: circumcised the eighth day, of the stock of Israel, of the tribe of Benjamin, a Hebrew of the Hebrews; concerning the law, a Pharisee; concerning zeal, persecuting the church; concerning the righteousness which is in the law, blameless. But what things were gain to me, these I have counted loss for Christ. Yet indeed I also count all things loss for the excellence of the knowledge of Christ Jesus my Lord, for whom I have suffered the loss of all things, and count them as rubbish, that I may gain Christ and be found in Him, not having my own righteousness, which is from the law, but that which is through faith in Christ, the righteousness which is from God by faith; that I may know Him and the power of His resurrection, and the fellowship of His sufferings, being conformed to His death,
Paul repeats this thought in...
Romans 10:3-4 For they being ignorant of God's righteousness, and seeking to establish their own righteousness, have not submitted to the righteousness of God. For Christ is the end of the law for righteousness to everyone who believes.
Dave