The Bible tells us that before a person is saved, they are without the power to act as God wants them to. They are bound under the power of the devil, the World and the impulses of their own flesh. (Ephesians 2:1-3) It will take divine power to make such a person spiritually alive and desirous of a different, Christ-centered life. If there, then, is one thing the Gospel makes clear it is that we are weak - so weak we can't do anything to help ourselves and so God must move toward us, take the initiative, and save us.
What has changed once a person has been born-again? Being saved, are they able to act on their own to be who God wants them to be? No. The weak person that God saved is the weak person God also must transform and empower. He is the Power Source for Christian living. (2 Thessalonians 5:23-24) No child of God can live righteously and do so consistently apart from total dependence upon God.
Oh, a believer has some small reserves of determination and strength. They can - for short spurts - appear to live as God has called them to. But, sooner or later, they run dry of power and desire to live God's way and fall back into sin. It can take many years of trying to live God's way in this way before a person is fully convinced of the fact that they haven't in themselves the capacity to be who God wants them to be. And when they really, truly know how bankrupt of power they are, then it is they begin to rely upon God as they should and so finally begin to conquer sin.
When I hear a Christian say, then, that he is trying to live God's way, I understand that he is not yet fully convinced of his own profound weakness and is attempting in his own human power to do what only God can do. By those trying to be holy there is often lip service given to God's power, some quoting of the "all things are possible" verse, a token prayer to God for help, but in the final analysis it is human effort trying to accomplish a divine end. And failure is always the inevitable result.
This is often because the life of Christ only manifests in the midst of our weakness and surrender - two things humans are loathe to acknowledge and do. Only when a believer has laid down his own self-effort and striving and yielded himself totally to God is God then able to fill him with His power and transform the believer's desires and behaviour. It often takes believers years to get to such a place - some never get there. The journey to the realization of utter personal impotency and the consequent submissive dependency upon God is, sadly, a rare thing.
2 Corinthians 12:9-10
9 And He said to me, “My grace is sufficient for you, for My strength is made perfect in weakness.” Therefore most gladly I will rather boast in my infirmities, that the power of Christ may rest upon me.
10 Therefore I take pleasure in infirmities, in reproaches, in needs, in persecutions, in distresses, for Christ’s sake. For when I am weak, then I am strong.
