Blessed be the God and Father of our Lord Jesus Christ, who has blessed us in Christ with every spiritual blessing in the heavenly places, even as he chose us in him before the foundation of the world, that we should be holy and blameless before him. In love he predestined us for adoption to himself as sons through Jesus Christ, according to the purpose of his will, Ephesians 1:3-5
There are many similar verses like this so for me, it is clear that He chose me. I am also confident that if it was left to my decision I would never have chosen Him, and if it was left up to me to continue in Him, I would have fallen away a long time ago. So I give thanks and praise to God my Saviour that He holds me firmly in Christ; and because of this I am confident that He who began a good work in me will bring it to completion at the day of Christ Jesus (Phil 1:6).
Charles Spurgeon summed up coming to faith like this:
One week-night, when I was sitting in the house of God, I was not thinking much about the preacher's sermon, for I did not believe it. The thought struck me, How did you come to be a Christian? I sought the Lord. But how did you come to seek the Lord? The truth flashed across my mind in a moment—I should not have sought Him unless there had been some previous influence in my mind to make me seek Him. I prayed, thought I, but then I asked myself, How came I to pray? I was induced to pray by reading the Scriptures. How came I to read the Scriptures? I did read them, but what led me to do so? Then, in a moment, I saw that God was at the bottom of it all, and that He was the Author of my faith, and so the whole doctrine of grace opened up to me, and from that doctrine I have not departed to this day, and I desire to make this my constant confession, "I ascribe my change wholly to God."