Romans 7:15-17

For that which I do I allow not: for what I would, that do I not; but what I hate, that I do.  If then I do that which I would not, I consent unto the law that it is good.  Now then it is no more I that do it, but sin that dwelleth in me.  

There is a battle between the flesh and the Spirit.  How many times do we have regrets when our flesh takes over, and we say something we shouldn’t.  We know it at the time, and we do “what I hate,” as Paul said.  Sin rises, and we don’t stop our flesh from taking over.  Our spirit can control our flesh as we develop in the word and speak our faith.  We have to exercise our faith, which increases our spiritual strength.