John 5:17-30 (NRSVCE)
Jesus calls God “Father,” which outrages the Jews as they see Jesus making himself equal to God. Why does it seem that way to them? Is a son always equal to his father? Fathers are the head of the household, right? So that should make the son less than the father, at least in some respect. Lucky for us, C.S. Lewis devotes an entire chapter of Mere Christianity to this topic.
The distinction Lewis uses is between “making” and “begetting.” We say all the time that Jesus is the only-begotten Son of God, and there’s a reason we use that particular phrase. When you make something, you are making something other than yourself. You are making a chair, or a car, or a hotdish (or a casserole, but that’s a distinction for another time). God made everything that is, and nothing that He made is God. It is all “other.” But when you beget something, you beget something of the very same nature as yourself. A tiger begets a tiger cub, not a lion cub. A chicken begets and egg. Or perhaps an egg begets a chicken. I’m still not really sure on that one. A human begets a human. It is impossible for something to beget something of a different nature. A human cannot beget a tiger, or a Porsche, or a Vulcan. You can only beget children. That is the fundamental relationship between father and son, and why the Jews were so upset at what Jesus said. If God is the Father of Jesus, it means Jesus is of the very same nature as the Father. It means Jesus is God.
But the relationship between Father and Son is also much more intimate than that between a human father and his human son. They are utterly united in all things, even their very wills are united. “I can do nothing on my own.” There are plenty of things my father does which I don’t do, and many things I do which he would never even want to do. My father wills to eat Dots candy, while I will to throw Dots in the trash where they belong. I will to spend my time in front of a computer screen, while he wills to work with his hands. We are still united in that filial bond, and a bond of friendship, but we are not so united that we will the same things all the time. The Son is totally united to the Father’s will.
It’s even more than this, however. Even since the Church Fathers in the first few centuries after the Resurrection, Christians have talked about the Persons of the Trinity, Father, Son, and Holy Spirit, being united not only in nature, not only in relationship, not only in will, but in action as well! If you look at any divine action in Scripture or throughout history, you can see all three Persons at work. They are all present in every divine action. A technical term for this unity of the Persons would be perichoresis, or circumincession if you’re more Latin-inclined. The idea here being that each Person surrounds (peri, circum) and contains (chorein, incedere) the others—a mutual indwelling. Though this is starting to get much more technical than I had intended. The point being here that though we use the terms Father and Son to describe this relationship, at the end of the day this is an analogy. The unity of Father and Son is far deeper than any human relationship. It is one of those mysteries which Christians have been contemplating throughout the ages, and one which we will contemplate forever.