The doctrine of the Trinity says that God is one but exists as three persons–the Father, the Son, and the Holy Spirit, each of whom is fully God. So far in my study of it here I’ve looked at Old Testament intimations of and New Testament evidence for it; provided Biblical evidence for each of these statements about it–(1) God is three persons, (2) each person is fully God, and (3) there is one God; considered some errors that have arisen through denying one or more of the three statements, in particular modalism or Sabellianism and Arianism; and begun examining the distinctions between the Father, the Son, and the Holy Spirit, noting in particular their different roles in creation and redemption.
Yesterday in our after-breakfast Bible reading time my family and I finished reading the section on the distinctions between the Father, the Son, and the Holy Spirit in Chapter 14, “God in Three Persons: The Trinity,” of Wayne Grudem’s Systematic Theology (Zondervan, 1994), which we’d begun reading the previous day. In what we read yesterday Grudem tries to explain with the use of diagrams and analogies the relationship between the three persons and the being of God and considered whether we can understand the doctrine of the Trinity. My saying “tries to explain” instead of “explains” isn’t a criticism of Grudem’s effort; it just recognizes the impossibility of explaining the relationship between the three persons and the being of God.
Grudem opens by explaining with the use of diagrams that:
1. God’s being is not divided into three equal parts, one for each of the persons of the Trinity. Instead each person has the fullness of God’s being in himself. Thus the Father possesses the whole being of God in himself, the Son possesses the whole being of God in himself, and the Holy Spirit possesses the whole being of God in himself.
2. The personal distinctions in the Trinity considered in my last post are not something added onto God’s being, their being differences in relationship but not a difference in being.
3. The persons of the Trinity are not just three different ways of looking at the one being of God, which would be modalism or Sabellianism.
Grudem then presents two analogies, one a diagram and the other a verbal analogy to try to explain how God is three persons and the being of each of the persons is equal to the whole being of God. In our family Bible reading we read what Grudem said about the diagram but didn’t read the verbal analogy. However my wife and I did mention analogies that we’d been told of when we were young, the egg and the shamrock. Another favourite analogy is water. The egg consists of shell, white, and yolk, all of which form one egg; the shamrock has three leaves but is one plant; water can be found in three three states–liquid, solid, and vapour. Unfortunately the analogies of the egg and shamrock have tritheistic (three gods) implications and the analogy of water has modalistic implications. After our discussion, I reread the helpful account of the search for analogies in Millard J. Erickson’s Christian Theology (Grand Rapids, Michigan: Baker, 2013 edition, pages 310-13).
Grudem closes the section in Systematic Theology on the distinctions between the Father, the Son, and the Holy Spirit by considering whether we can understand the doctrine of the Trinity. His answer is that, although we can understand that God is three persons, each person is fully God, and there is one God because the Bible teaches each of those statements, we can’t understand how to fit the three statements together. It is a mystery or paradox. I agree with him.