How did God come to be? I know this is an old question, but does anyone have any new ideas on it? 

One argument is that God has always existed, but why should anything exist at all? How could this happen?

Another approach is that God (and possibly God's creator(s)) came into being at some point, before He then created the universe. But how could there to be a point at which something began to exist, where before there was nothing? Scientists argue that something can come out of nothing, and that this happened at Big Bang. Some of them say 'Nothing is an unstable state - it is not surprising that something has emerged'. However their 'nothing' is a particular condition of space-time, under various science laws that already exist; why should there even be physics laws? 

I'd be interested if anyone had any thoughts? Thank you.
The Christian answer to this is simple and ancient. God is eternal and has always existed. He does not have a creator. He is the 'first cause', or 'uncaused cause'. Speculation about how that came to be (bearing in mind that 'came to be' is a phrase implying time and causation, which may not be appropriate) are just speculation on the part of individual Christians.

It should be said that a small minority of sects, notabley the Latter-Day Saints, don't agree with the above statement.