The Trinity

[Papewaio]

This is all interesting but who created God?

Or did nothing exist before Him and then he sprung into being whole?

[Vincent Butler]

This is all interesting but who created God?

Or did nothing exist before Him and then he sprung into being whole?

No, he has always been. Time is essentially(I say essentially because God created the means by which we measure time) a man-made convention. Before creation, there was no time. 2 Peter 3:8 makes it plain that God is beyond the limits of time.
I will let Rhy answer in detail, but I felt that this thread, and Sigurd's long post did need to be addressed while he is preparing his response.
That is one of the remarkable things about the trinity, and we as humans need not be able to fully understand it. Christ is a part of one entity. He is his own individual part of that body.

"For in him dwelleth all the fulness of the Godhead bodily." Colossians 2:9

Rhy, I hope I didn't steal part of your response.
Sigurd, I am aware of the Elohim reference in Genesis, it is referring to the three parts all being present at creation, at least, that is how I understand it, and it does not conflict with the teachings of the trinity as found in the Bible. Principle rule, interpret Scripture with Scripture.