We are here because otherwise, we wouldn’t be.
Confusing title, but bear with me. When asked about the origins of the universe I often shrug and simply admit that I have no idea, whatsoever. Of course, it doesn’t mean that since we lack an understanding of something, then there has to be a magical sky daddy or at least an invisible pink unicorn living in a celestial teapot who spoke the universe into existence — now, this blunt “I don’t know” should not affect my position as an atheist, but I have often been told that “If you don’t know for sure, then you need faith to claim there is no God”. However, the utterer of these words should at least educate himself that, as an atheist, I do not claim that there is certainly no God. I simply refuse to believe in one until evidence is presented. Theists claim there is a god. Surely the theists carry the burden of proof.
Intelligent design proponents will repeat these arguments in your ears like a broken record. The earth is fine-tuned for life! The universe is fine-tuned for life! I reserve the right to repeat my answer, too, like a broken record. Animals on earth, including us, die from the heat, and they also die from the cold. There is this one thing called the habitable zone, and earth is located within it (as opposed to Venus). You wouldn’t call Venus fine-tuned. It is some pretty bad design, but who am I to question the whim of the almighty pink unicorn?
Anthropic principle here. The universe is not fine-tuned for life because life as we know it evolved in the universe. Perhaps if some of the constants were a bit “out of tune”, a completely alien life-form might have been spawned instead of us, and the creationist alien might consider the universe fine-tuned. We cannot call the universe fine-tuned because we do not know what fine-tuned is.
However, reason tells me that if our universe is anything, it isn’t fine-tuned for life. We live in this little remote corner (metaphorically speaking), and for all we know, we might as well be out here all by ourselves. Life in the universe is most likely rare — but it happened, and we are here because it happened, otherwise, we wouldn’t be here to even ponder the question, right?