Paul [as Saul] was a driven man. We might say driven by fear and rage and a fanatical fundamentalism which caused him to assent to the killing of Christians.
In this, we might say his willpower was strong. But at the same time, he knew that his willpower was wrong. He had conscience problems because that which he was fulfilling by law, was in opposition to that which was obviously right and wrong. “It is hard to kick against the pricks”.
In Romans chapter 7, Paul looks to his inner nature and what transpired there. He found that his willpower was non existent when it came to doing what was right, because there was inner conflict which confused and frustrated his wish to do the right thing. He ended up in a situation devoid of his original right desire, and instead, the one which he did not desire, resulted.
He was driven by his captivity to the law, which, in turn, captivated him to the will of his flesh, so he could not deliver the demands of the moral law, but only the executive law, the law which represented the “wrath of God”. His agreement with the whole of the law was his wish; he was consentual to its requirement, but he could only enact and represent the condemnation of the law and not the mercy of the law.
He knew that this was wrong, and he was torn apart inside by the conflict caused by what the law required on the one hand, and what he was capable of delivering, on the other. He was living with the wrath of God, and so was a wretched man.
This defeated man whose willpower was reduced to wishful thinking, and whose actions were in slavery to his reactive flesh, reactive to law because of the condemnation of the law, found new direction when he was revived to life through the revelation of Jesus. His tortured spirit was set free from its prison of futility fear and death.
His willpower which was in captivity to his flesh, in captivity to sin, was now given a new direction. He was empowered by the Spirit to enact the willpower of God, to represent God in all that he was, did, and said. His will was now singularly set on that which engaged with and fulfilled, the will of the Spirit. He was a driven man again, but this time “He knew the one whom he had believed”. Nothing short of death could prevent him from obeying the Spirit of Jesus which now lived with him and in him. He was now representing on earth, the very person of the Jesus he had come to know.
What caused such a change? It was the Spirit of God, the Holy Spirit, the Comforter, the risen Christ who now walked with him. We can do nothing of ourselves. We need to know this same Spirit that changed Paul’s life, that became his life, and who can change us also.