A: "You ask where God came from...this is something that is difficult for one human to answer for another. Being finite humans, we are accustomed to things having beginnings and endings; the infinite, non-beginning and non-ending nature of God is hard to wrap our minds around. But we do carry an infinite spark of this infinite God within our minds, and at some point in our eternal future we will grasp more of this mystery.
The truth is that in this earth-life we simply do not have the capacity to fully understand the mystery of God, and that is where our faith has to become active. We humans are just not yet able to fully satisfy our desire to understand, as much as we would like to...on normal planets, the eternal nature of God is a subject upon which there is no doubt, but here on Earth, we must rely on faith and experience alone to satisfy our doubts. The Urantia Book is a great help in this regard as well, being a new revelation of God that opens up the reality and nature of God in a way that helps make God more accessible to us than ever before.
Over the years, we have received this question in several forms in our "FAQ" and "Life's Toughest Questions." I am giving you the links to those questions and answers below. I hope that you will find an answer here that will help you through this doubt that you are experiencing. Within these Q+As are numerous links to passages from The Urantia Book, and pages on our site that will give you a great deal of additional information and inspiration.
...where did God come from?
Where was God before the creation of heaven and earth?
If there is God, who created God?
Does God really exist?
And remember—honest doubt is something that all believers grapple with from time to time. There is nothing wrong in having honest doubt. When you find yourself faced with doubt, there is a simple prayer that will help you through it:
"Lord, I believe. I pray you help my unbelief."
I hope you have gotten a satisfactory answer to your question today. Please write back any time!"