Paul's formula, of Christ's love and giving of himself

There is a phrase Paul uses three times in the New Testament, almost like a formula, and I can't help but think it is a favourite phrase or expression of his, something he loved to dwell-on, and a "game-changer" for his life. It is simple but profound, and occurs these three times:

I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me [Galatians 2:20]

And walk in love, as Christ loved us and gave himself for us, a fragrant offering and sacrifice to God. [Ephesians 5:2]

Husbands, love your wives, as Christ loved the church and gave himself for her [Ephesians 5:25]

Often the Scriptures speak of God giving his one and only Son, and also of the those evil men who gave Jesus over to be crucified. But in Paul's expression he makes clear that Jesus gave himself, and that was a measure of his great love for sinful, undeserving people. The LXX uses some similar wording in Isaiah 53:12, and perhaps Paul's phrase arose out of a meditation upon that verse, as well as a consideration of Jesus' own words in John 10:18 etc. Whatever the origin may have been in Paul's thinking, it is a truth that God has recorded in the Scriptures to change our lives. How much are we willing to give to him who loved us so?