According to Paul’s sermon in Acts 13, God chose Israel as His favored people, and He appointed some to believe Paul’s gospel message. Paul also talks about God’s “selection” of Jesus as the Savior, in quoting Psalm 2:7; “You are my Son, today I have begotten you,” (or the NIV rendering; “You are my Son, today I have become your Father.” I didn’t get into it, but this is a tricky verse and quote! Why? Because it almost sounds like Jesus was not God’s Son, then one day “became” God’s Son. That’s essentially what an ancient heresy known as “adoptionism” teaches. This teaching, denounced as heretical by the church, states that Jesus was not God’s eternal Son by nature, but was simply a good man that God “adopted” to be the Savior. They would look to verses like Acts 13:33 and Hebrews 5:5 to back up their views. Why do we know that adoptionism is wrong, and that Jesus did not become God’s Son, but always was God’s Son? We go back to verses like John 1:1; “In the beginning was the Word, and the Word was with God, and the Word was God.” Such verses show that Jesus always was the Son incarnate, and did not become so. That said, how we do understand verses like Acts 13:33 that almost sound like Jesus became the Son of God at a certain point in time in His earthly life? A short answer is that these verses do not teach that Jesus became God’s Son, or was chosen/appointed as God’s Son at a certain point in time. Rather, these verses assert that, as Jesus progressed in His earthly life and ministry, He fulfilled His role as God’s Son and our Savior. In His ministry, He carried out His office and role as the Son and Messiah, and in so doing performed what He was eternally appointed by God to do from before time began. God’s sovereign plan was always for Jesus—the incarnate, eternal Son—to fulfill in time His eternal mission of salvation.