Originally posted by yo its me
But there's no way we all sprang up from a big bang of space that arrived from nowhere with two atoms that arrived from nothing.
That is because you are thinking too simplistically. In the vast majority of cases, you don't get complex molecular structures that give the illusion of "life" out of less complex structures, but given enough time and space, and it is plausible.
All it requires is the right conditions, billions of years, and you can get a molecular structure that can self replicate. From then on, natural selection takes over and newer more complex forms develop.
It is worth noting that experiments have been done by the biochemist Sidney W Fox back in the 50s and 60s which demonstrate one possible way on which life had formed on this planet. Where he studied the spontaneous formation of peptide structures under conditions which duplicated possible conditions millions of years ago. Certainly these were in closed clean systems, because if you create these structures and put them out into the world today, bacteria that already exists would destroy it.
Since Darwin, there are many thousands of experiments that fit so well with natural selection and evolutionary theory, that it is accepted as the norm now within the scentific community. All they experiment with these days are the finer details.
You may argue "how is the Earth just the perfect conditions to sustain life? That must mean the Earth and life had been designed to do so". The point is that life evolved to fit the conditions, not the other way around. Evolved to the stage where we could come to the point to ask that question.
Life can easily (and may well do) evolve on the other side of this galaxy, where these life forms ask the same kind of questions. Natural selection evolves life that fit the environment, so it seems "perfect".
This reminds me of Douglas Adam's puddle:
"Imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in, an interesting hole I find myself in, fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, it's still frantically hanging on to the notion that everything's going to be alright, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for."