Paul came to that understanding of what he was in himself, apart from the grace of God, and what he had become in Jesus Christ. He did not go on from that point to become more and more self-righteous. As he entered into this process of growing in the Christian life, he progressed in an understanding of God and his nature, as well as of himself and his sin. He recognized himself not to be increasingly righteous, but increasingly sinful.

The first passage where Paul talks about his past is Galatians 1:13, where he writes, “For you have heard of my previous way of life in Judaism, how intensely I persecuted the church of God and tried to destroy it.” Paul believed that by working against the church he was serving God as a faithful Jew. He, of course, did not realize at that point that the same God he was claiming to follow was establishing the very church Paul was persecuting.

I find it very interesting that in writing this letter to Timothy and having begun it as he has with an emphasis upon sound doctrine, Paul now speaks in a personal way of how the grace of God in that doctrine came to him. As he does, we recognize that here is not a proud man who somehow has all of the doctrine and therefore lifts himself up for recognition by men and women, but who in the light of the very nature of the gospel of God's grace in Jesus Christ recognizes himself to be a sinner. 

 This book has been entrusted to us. This is a precious possession, and the gospel that it contains is precious as well, precious beyond all possible price. Let's guard it. Let's love it. Let's live by it. Let's read it. Let's study it. Let's share it. Let's talk about it. Then, by the grace of God, others will come to love these truths too.

Having mentioned the controversies, Paul wants Timothy to counter them and to stand for the truth of God once revealed to the saints, and make sure that the churches stand for that as well. That is what Paul means when he talks about sound doctrine.