Flesh vs Spirit

Have you ever wondered why you are not as good a Christian as you know you ought to be?
When you were saved, the old sinful nature you had did not die. It is still there. The Bible calls it the flesh, old man, and the carnal (worldly) mind.
When you were saved, your SPIRIT became alive and functional. An unsaved man walks after the flesh-his spirit is dead. (Ephesians 2:1) A Christian has both the fleshly and the spiritual natures. That is where your battle comes in. Notice all the scriptures that mention these two natures inside of you;

Matthew 26:41
Romans 7:14-25
Romans 8:5-7
Romans 13:14
Galatians 5:17-19
Galatians 6:8
Galatians 5:19-21
Galatians 5:22-23
Romans 8:14
1 Peter 2:11
Jeremiah 17:9
1 Corinthians 15:51