For I am the least of the apostles and do not even deserve to be called an apostle, because I persecuted the church of God. But by the grace of God I am what I am, and his grace to me was not without effect. No, I worked harder than all of them - yet not I, but the grace of God that was with me. Whether, then, it was I or they, this is what we preach, and this is what you believed."
I am what I am
by the grace of God
We could all say that same sentence! We are all sinners and Jesus Christ saved us!! Paul was deeply humble. He knew that he had worked hard and accomplished much, but only because God had poured kindness and grace upon him. He recognized God's work in him, having once been a Jew who persecuted the christian church.