This question has a false premise. It assumes that God was, in fact, created. For something to be created, it must have a beginning. God does not. I hesitate to use the word, “eternal”, but I will say that God *transcends* the time and space limitations of this universe. This is not as unscientific as it may sound. Many scientists postulate a limitless “mother” universe which gives “birth” to finite “child” universes like the one we find ourselves in. That sounds almost religious, doesn’t it?
Prayer is such an intimate act, a place of vulnerability. It is, hopefully, when we are our least guarded, our most honest selves. And this is good, of course; this is as it ought to be. When we come to God, we certainly want to come as honestly and openly as we can; we want to be our truest selves before him. Prayer lets us be in a place of need.