Way to demonstrate your lack of understanding of what a scientific theory is. Do you question the theory of gravity as well?
Now you're trying to take me around the barn but in the process you put me on the right path. the big bang theory measures the movement of known particles in the universe and determines they are moving apart. it Therefore assumes that those particles were together and exploded propelling them thus the big bang theory.
As such the movement is known the bang is not known thus it is a scientific theory not fact based but our best guess using very limited scientific knowledge.
there could for instance be even larger bodies that we have not discovered on opposite sides of our universe that are exerting forces similar to gravity causing that movement . that would be one possible cause of that movement and if later discovered would completely rule out big bang and then take us in a different direction.
certainly external forces pulling rather then internal propelling is a realistic possibility
we are but a fraction of that incredible universe that exists and all things are possible even the possibility that our god is a much larger child playing with his planet and galaxy toys. who knows.
but to totally discount a higher creating force when so much of our universe is undiscovered seems to be a bit premature. lets have this discussion again in a couple zillion billion years when we come back through time travel or such.