You are absolutely right: "An observer shifted in just the right way would observe the vacuum teeming with life while another would find the entire universe entirely lifeless." The problem (if you want to call it that) is that science is at an impasse. It has probed the depths of material reality and determined that there are events at the quantum level whose cause cannot be determined by the scientific method
even in principle. Some scientists, perhaps most, assume that randomness is therefore the ultimate cause of everything. The “
God of the gaps” is replaced with “
chance in the gaps.” It's a philosophical assumption that requires the blind faith of a religious fanatic to believe.
How do I know that everything that has a beginning has a cause? Anything can be rationalized, so let's not make it a philosophical question. Facts, the pride and joy of atheism and the foundation of the scientific enterprise, is based on the assumption that every effect has a cause. So, let's start from there.
To grasp something, to prove it, one must isolate the object from from everything else. But, ironically, scientific reductionism has verified that either every part of creation is also the whole, or the moon isn't there when no one is looking. (Here's an interesting article on that from
Nature magazine:
Quanundrum). If life isn't just a part of creation but the whole of creation, then there are mysteries that cannot be grasped. The pursuit of highest truth necessarily leads beyond the confines of material science.
When scientific reasoning falters in an encounter with an insurmountable problem, “I dunno” is invariably the fallback position. That it's a vacuous position and epistemologically worthless doesn't seem matter and therefore represents a failure to follow reason to ultimate conclusions. It's next of kin, “prove it,” can't reason its way out of a paper bag if it were given a road map and instructions.
I do not have the words to describe how truly pathetic "prove it" is. Atheism claims that it is the hallmark of reason, but began with a gross misrepresentation of the cosmological argument—a lie—and the lie (post #1050) is ignored as though it has no bearing on atheism's intellectual honesty.