Already did. Several times. But your religion is making you reject science.
The Big Bang | Exploratorium
www.exploratorium.edu
The Beginning of the Universe | Alexander Vilenkin | Inference
Despite the perplexing questions associated with the universe having a beginning, the BGV theorem shows it must have had one. Alexander Vilenkin describes the theory of quantum creation, and why it means that the universe both could have a beginning and be uncaused.inference-review.com
What Happened Before the Big Bang?
An exploration with a mathematician about what precedes the Big Bangnow.tufts.edu
Borde–Guth–Vilenkin theorem - Wikipedia
en.wikipedia.org
What is the cosmic microwave background?
The cosmic microwave background can help scientists piece together the history of the universe.www.space.com
When was the first light in the universe?
The speed of light gives us an amazing tool for studying the universe. Because light only travels a mere 300,000 kilometers per second, when we see distant objects, we're looking back in time.phys.org
Redshift - Wikipedia
en.wikipedia.org
Do any of those links contain claims by mainstream science that the god played a part?
And I have told you that there are alternative theories. None of which requires your favoured god to play a part.