option 1) God has always been around and then set about making the uinverse.
This is not the simplest explanation. Where did god come from, why did he set about making the universe and why did he make it this way it is a horifically hostile place? How did he learn to create universes? What tools did he use? How did he concieve of something that did not exists and then fabricat it, in a week to boot? Where is this god then anyway, we can't observe or interact with him in any measurable way?
Option 2) The universe has always existed.
We have a compelling scientific narative based on evidence for the origins of life the universe and everything back to the big bang, and some compelling hypothesis for things beyond that and it all works without an overseeing agent.
This narative is based on reasoned and evedence backed observations of the universe something we all experience.
Between the two the second is clearly the simpler explanation.