We are here to procreate. If you're looking for more reason than that, I believe you are simply having trouble accepting the reality of our situation. As for how we're here, science is attempting to answer that question. Also, the big bang is incomplete, but that does not mean it is inaccurate. It may be complete eventually, or whole new ideas may develop.

 As for your comment about people who don't like religion, I don't like religion because it's not true. It's made up. We use science as evidence against it because...well...that's exactly what it is. The bible claims that the Earth is 6,000 years old. 'Nuff said.