The Scriptures often call God our Father. In the well-known Lord's Prayer: "Our Father, who art in heaven, hallowed by thy name." Jesus often speaks of when you prayer, call up your Father God as your Father. That's a very important label for God, and it gets at the mystery of the Trinity. Usually when the New Testament uses the word God, it's usually referring to the first person, and this first person is the father of his son. So, when there's a father, there has to be a child, and in this case it would be the son. And this relationship goes back to eternity. There was no start in this relationship. God, the first person, has always been the Father of his Son, and his Son has always been the son of his father. And that goes back forever. And there has always been the spirit of the Father and the Spirit of the Son, and the three are inseparable. They're always with each other. Not only with each other, but a lot of times you can say the Son is in the Father, the Father is in the Son; they interpenetrate, so, there are not three different Gods. There is only one godhead, one divine nature that's indivisible, and three persons. So, they often use the word Father to refer to the first one first person. And so the first person is seen right off the bat as in relationship to the second person. He's the, what? eternal source, eternal begetter of the Son, and so we say in the Nicene Creed that the Son is begotten of the Father, not made. So, he's not a creature, he not a creature created out of nothing; he's a Son begotten of his Father from eternity before all worlds. From the Nicene Creed: God from God, Light from Light, very God from very God, begotten, not made and that the Son is of one substance with the Father, and through the Son all things were made so that the Father through the Son made all things. So, the word Father is very appropriate for referring to the first person of the Trinity.