#my pastor recently did a sermon series on the Trinity so I'm very prepared here

[greater-than-the-sword]

what metaphor for the trinity do you suggest?

The only metaphor I can even sort of recommend is the one suggested by the Bible with the idea of Christ being the word, God the Father being the speaker, and the Holy Spirit being the breath. Some have also come up with the idea of the triple flame from a single source, though I haven't heard a lot of teaching on this specific one.

Yet, to have a metaphor to directly explain the Trinity is impossible, since it is not fully comprehensible to the human mind that one being can be three persons. But, some metaphors are worse than others. Therefore no metaphor should dominate our thinking. Also, when explaining the Trinity to a beginner it's important not to start off by bending their thinking toward a potential heresy like modalism or partialism. This will give them a starting misconception of what God is like.

All three persons of God are fully God and have all the complete authority and power and every attribute of the Godhead. God doesn't switch between or "act as" the different persons. The Father, Son, and Spirit coeternally coexist. At the same time they are not three gods, but share the same essence. It is better just to give a theological definition of what the Trinity is than to boil it down to a bite-sized metaphor that you can fit in your hand like a clover or an egg.