How can be Trinity Eternal?

Question

It's said in Summa Theologica that the trinity ist eternal, three persons each one being G'd a well known fact in Christianism. I'd like to know, what is the greek explanation or the following (Matthew 28:19) and if it was very changed (by translation):

Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, (ESV)

And we see a distinction amongst three words, why this happens if indeed G'd is One, and why would it be that they would be G'd if G'd is One, Aquinas says that He is one times one times one, this is, He isn't three as a number, but I'd like to point out that even though this seems true, isn't there a dialectic thinking in this?

And in Ephesians 4:6 the following, just as a reflection:

One God and Father of all, who is over all and through all and in all.

More, I'd like to add the following: if G'd is One, then isn't everything and everyone G'd? For if they weren't Him, then He wouldn't be One (the contrapositive), then if this stands, meaning that there is just Him, why is there a perception of evil which isn't Him?

obs.: the title is called if trinity is eternal as a way to say if it's the reality that trinity attempts to explain or G'd He Himself in an absolute manner

Answer 1

The Trinity doctrine is a way of expressing who God is, for Christians. It is a form of words that grapples with the concept of the inconceivable - the being of the one God who is Almighty, who is infinite, who is Spirit, and who is Creator of everything. We are finite creatures who come into existence at a certain point in time, then who die. We are mortals. Deity is immortal.

This means that if Deity is immortal (having no beginning and no end), and that Deity is triune in being, then the triune God is eternal. That answers your question.

However, you then go on to ask two more questions which indicate that you do not know what the Trinity doctrine teaches/says about the one God whom Christians worship. You need to sort out in what sense God is one. I suggest you ask a separate question on that (though it's already been answered here on Stack, both in Hermeneutics and in the Christianity sites.) Your other question about "the perception of evil" also requires to be dealt with separately. You are jumping from one thought to another, but if you gain clarity first on what the Trinity doctrine actually says (and does not say), you will be in a better position to tackle these other deep matters.