I think I understand you now.
In the spirit of interfaith dialogue, I'd like to say that for me, the corrolary to God not depending on a prior cause is that this appears to be the case for the universe itself. To me, things in the world do exist by virtue of their existence. That everything is transient and subject to arising, change, and decay, does not contradict their inherent, self-apparent existence. Tongue-in-cheek, I might say that the universe does not disappear when I stop believing in it: it did a fine job of existing long before we human beings started pondering these questions, and it will continue on existing (subject to its own arising and eventual passing) for a long time after we will be gone.
I'm saying this in the spirit of open discussion of world views, not to disparage anyone elses's faith.
The best medieval philosophers in Western Europe held that human reason is unable to resolve whether the universe is eternal or had a beginning. This seems to be the case regardless of the latest findings about the process of early expansion of the universe. A singularity at the origin of expansion could have been eternal. We may have common ground regarding these points about the universe. Is the question of the possible eternity of the universe different from existence of the universe?