How much more common sense do you possibly need, eh?????
All that science can speculate is the universe 1 planck time after the big bang. Prior to that, the fundamental quantities of physics -- mass, length and time -- are reduced to irrational quantities. That is as far as science can go.
What is speculated here is a space-time singularity -- everything that is the universe crumpled by infinite gravity to a dimensionless point. Common sense would tell you that it would remain in its state -- UNLESS AN 'EXTERNAL FORCE' ACTS UPON IT -- the same 'external force' your atheism stupidly denies.
And that is not all. If you had taken the time to understand general relativity instead of quantum mechanics, you would have come across the flatness problem. The initial conditions of the universe seems to have been fine-tuned to very exact quantities to derive a geometry that we see today. Any minute deviation from these exact quantities would have been instantly fatal.
I have asked this question a lot of times before and not a single one of your loud-mouthed atheist ilk had the audacity to answer honestly.
If someone were to win the lottery for a week straight, what are you inclined to believe? That he is lucky or he somehow cheated?