First of all, I'm Catholic, not protestant, so the Bible is considered a record of revelation, not the sole source thereof. Things like evolution, or any other scientific theory are acceptable. So any and every valid scientific conclusion is acceptable and integrates - there's no substituting Bible passages for scientific facts going on here. Scientific evidence is a must for any observable phenomena. That does not preclude the possibility of observable phenomena, which has no physical cause - but such things are treated with skepticism, and on very rare occasions conceded to be miracles.
Ultimately the attribution of the cause of existence is always a belief. Science only deals with physical causes, but obviously physical causes cannot generate new matter/energy/forces, but can only modify/influence them. The best science can give us is what kind of pre-existing existence could give rise to the type of existence we see in the physical universe. There are a plethora of theories about the origins of the the big-bang, but these are speculative - and even then, the origin of the big-bang's existence could never be verified, let alone observed/measured/etc. When it comes to existence (and I am not limiting it to the existence of this universe, for there may be many quite unlike our own), one either believes such existence is eternal, or caused by some other eternal existence. Believing one theory, or another is simply a matter of choice, because there is no actual observable evidence, other than the universe itself.
Catholics believe (in the correct sense of believe - ie. without irrefutable evidence) that our existence was caused by a non-physical, eternal, conscious existence - ie. by God.