When Jesus taught His disciples to pray “our Father,” He gave us the key word in our understanding of God (Matthew 6:9).
In the Old Testament
It was not entirely new. Moses was instructed to give God’s message to Pharaoh: “Israel is my firstborn son” (Exodus 4:22), implying that God was Israel’s “father.” And what was implicit there becomes an explicit use of “father” in the song of Moses. There He asks Israel: “Is he not your father, who created you, who made you and established you?” (Deuteronomy 32:6).