I'm sure that will be seen as 'preachy', BD.
From what I've seen in this thread, I would say that a common issue that runs through the non-deist's thoughts is that God is a being on the same order as humans, only omnipotent and omniscient.
This certainly isn't what Catholic theology says on the point.
To put it another way, if a human were to be omniscient and omnipotent, he still would not be God (or even 'a god'), because his nature is not God's nature.
Christ, BEING God, would not fall under the above.
I guess what I'm trying to say that one nice thing about a Trinitine God is that there's no way to understand such a being (from a human perspective), and so there's need to try.
For those that want a non-preachy approach to Christianity, I can only refer you to Chesterton's Orthodoxy. Lewis's Mere Christianity would also be profitable, I think.