God as Trinity: The Three Statements That Must All Stand

Early church theologians eventually reached a consensus on how to talk about this, and it came down to three statements. Any view of the Trinity has to keep all three without violating any of them.
First: God is three persons. Some passages co-identify the persons with each other, to convince us they are the same God. But the Father is not the Son, and the Son is not the Spirit, in terms of personhood. And note this carefully - the persons are not parts of God. They are God.
Second: each person is fully God. Not partially God. Not merely divine, in the sense of being something like God. Each person really is God.
Third: there is one God - one unique and incomparable God.
Scripture affirms all three of these, which is why all three have to be affirmed. The struggle has never been whether they are taught; it is how to understand their relationship to each other. Every historic error is simply one of these three being quietly dropped to make the other two easier.
That is a useful test to carry. When you meet an explanation of the Trinity, ask which of the three it just let go of.
Scripture links:
- Matthew 28:19 - the name of the Father and of the Son and of the Holy Spirit.
- John 1:1 - the Word was with God, and the Word was God.
- Deuteronomy 6:4 - the LORD our God, the LORD is one.
Drop one and you have left the teaching.