Furt has a cool, if unsatisfying, answer. “God is the first, uncaused Cause.” (paraphrase) It’s the only possible answer unless you like “sorry, it’s turtles all the way down!”
Now, investing this First Cause (which I think even the atheist crew could give intellectual acceptance to, because all It is, going into the far turn, is the ontological basis for everything else) with personality, characteristics such as goodness and love, an active interest in humanity (why?), etc. is what we’ve been hashing around for the past several weeks here.
One quick comment: What was God doing “before” the Big Bang? may be a meaningless question. According to traditional theology (give me this for the sake of argument for the moment), God exists in eternity. Eternity is not perpetuity; it is a timelessness in which all times are equally present. Time only started with the Big Bang.
If you travel north or south, you can arrive at a point (the pole) at which you are the furthest north/south and any continuation makes you going south/north. But that is not true for east/west. If you keep going east, you do not reach a point at which you begin going west. If you go back to the Big Bang, there is no “before” to go to, because there was no matter/energy present “before” the Big Bang to define space and time.
Snippy…if you like science fiction, a couple of stories that explore your concept: “The Last Question” by Isaac Asimov (a little dated at the beginning from having been written in the 1940s/50s when mainframes were all there was), and the Spider Robinson series which includes three books:
- Time Pressure
1-2A. Deathkiller, a revised portmanteauing of 1 and 2.