Romans 7:18-20 For I know that in me (that is, in my flesh,) dwelleth no good thing: for to will is present with me; but how to perform that which is good I find not. For the good that I would I do not: but the evil which I would not, that I do. Now if I do that I would not, it is no more I that do it, but sin that dwelleth in me.
Galatians 5:17 For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would.
2 Corinthians 3:5 Not that we are sufficient of ourselves to think any thing as of ourselves; but our sufficiency is of God;
Matthew 26:41 Watch and pray, that ye enter not into temptation: the spirit indeed is willing, but the flesh is weak