E33: Q39 Q40 Why do you call the first of the three divine Persons “Father”, and what does that mean?

Question 39: Why do you call the first of the three divine Persons “Father”?
Question 40: What do you mean when you call God “Father”?

39. Why do you call the first of the three divine Persons “Father”?
    Our Lord Jesus Christ is the only divine Son of the Father. He called God “Father” and taught his disciples to do the same. God gives believers his Holy Spirit and adopts us as his children, enabling us to call him “Father.” (Deuteronomy 32:4–9; Psalm 2; Matthew 6:6–9; John 5:17–23; Galatians 4:1–7)
40. What do you mean when you call God “Father”?
    When I call God “Father,” I declare that I was created for relationship with him, that I trust in God as my Protector and Provider, and that I put my hope in God as his child and heir in Christ. (Genesis 1:26–27; Psalms 68:4–6; 103:13–14; Matthew 6:25–34; Romans 8:17–21)