Many passages in the Jewish Scriptures, which Christians call the Old Testament, describe the people of Israel as God’s son or child (Exod 4:22,23; Jer 31:20; Hos 11:1), or declare how God has been a father to the people (Deut 32:6; Isa 64:8). These expressions show the special relationship God has with his chosen people.  But the title, “son of God,” is also given to an unnamed king of Israel (Ps 2:7). God said that King David is “my first-born son, and he will be the ruler of all kings on earth” (Ps 89:27). David is also told that one of his children would be God’s son (2 Sam 7:14; 1 Chr 17:13). The later prophets spoke of the faithful members of the people of Israel as God’s children (Isa 43:6; Hos 1:10).
In the New Testament Gospels, Jesus is the only true Son of God, as is declared by the voice from heaven at his baptism (Luke 3:22). The religious leaders who wanted to have him put to death asked him if he was the Son of God, and he said that he was (Mark 14:61,62). The Gospel writers show that even the devil recognizes Jesus as Son of God (Luke 4:1-12), and the demons that he brought under control do so as well (Mark 3:11; 5:7).

Most important is the direct claim of Jesus in Luke 10:21,22 to be the Son of God who has been given God’s wisdom, which he shares with those who trust him as one sent by God. Before Jesus was born, he was identified by the angel as the Son of God (Luke 1:32-35). Matthew 2:15 quotes Hosea 11:1, which speaks of God bringing his Son back from Egypt. Paul wrote that Jesus is by human birth the son of David, but he is now Son of God, because God raised him from the dead (Rom 1:3,4; see also Gal 2:20). The author of John’s Gospel wrote that Jesus is the Son of God (John 1:14) who was sent by God into the world to save his people from their sins (John 3:16,17). He does God’s work in the world (John 10:34-36), and is one with God (John 17:1, 22). And it is because of what the Son has done that people who put their faith in him can also claim “the right to be children of God (John 1:11-13).