“But by the grace of God I am what I am, and His grace toward me was not in vain; but I laboured more abundantly than they all, yet not I, but the grace of God which was with me.”

Solely due to God

Paul is saying that all that he has done, all that he has become, should be recognised as a wonderful achievement, but that none of that was due to him. It was solely due to God, to whom all praise should be given. And even the effort Paul put in towards this (I laboured more abundantly) was not from himself, that too was a gift.

The name of God

The first phrase of Paul echoes the name of God in Exodus 3:14:

And God said to Moses, “I AM WHO I AM.” And He said, “Thus you shall say to the children of Israel, ‘I AM has sent me to you.’”

And when Jesus used this title for himself in John 8:58, it provoked the Jews to try to stone him:

Jesus said to them, “Most assuredly, I say to you, before Abraham was, I AM.” 59 Then they took up stones to throw at Him;

What I am

But in the phrase Paul uses, he doesn’t claim to be God, as he uses the word “what” rather than “who”. That which he has become is due to God alone, to the Holy Spirit dwelling within him.

Romans 8:11, “He . . . will also give life to your mortal bodies through His Spirit who dwells in you.”

This is confirmed in the last phrase, “yet not I, but the grace of God which was with me”, which echoes Galations 2:20 “it is no longer I who live, but Christ lives in me”

From the bible we learn that our relation to God is fully restored when when we believe in Jesus and accept his free gift of salvation.
But a second gift is how we get to enjoy that restored relationship here and now, as the Holy Spirit lives in us and does all sorts of things which are not within our natural power. It’s a trap if we take pride in any of that, the glory and our boasting is for God alone.

The things I now find myself doing are things I enjoy beyond what I could have wished for, but only as they are in accord with God’s plan for me.