There is not that much evidence. Your brain and the chemical reactions cannot explain everything. NDE (Near-Death Experiences) is one example of the many phenomenons science fails to explain. Although some people claim the "tunnel" is explainable by the mecanisms following the death of your brain, there is still no evidence and a lack of explanations for many details brought back from people who experienced death. Neurosciences can explain the mecanisms and a few locations working throughout specific thoughts and emotions, but there are still major holes in our understanding. We can explain the "where" and the "how", but not the source. Through all the things you can do and feel, all the passions you have, your projects and the people you love, if you want to believe it's all chemical reactions, of course you will find many people who will share your belief, and I used to think the same, until I came to the evidence I'm sharing with my bro Tru Principle, who I know got pretty much the same ways of seeing life as I do, except that he believes in Allah and I believe in God, which end up being the same. Science explains evolution, but not the "why". Rewind time as far as you want, you will still fail at understanding the big picture. Something has to have always existed, a concept which the human brain cannot visualize, but only conceive. Either that something is nothingness, or an intelligence we call God. Order requires intelligence, and the universe is ordered. You can call my belief the Intelligent Design, cuz I don't believe in coincidences.
For all those reasons I believe I have a soul, but I think a soul is also something you have to work for, some people are lost forever.