I think it is easy to struggle with this one. I have watched so many others try and reconcile their heads and their hearts. Sometimes, we think we know something with out heads, but we just can't feel it in our hearts. But I don't think belief is something that we find in our heads. It is something that grows in our hearts.
I have had people that I love ask me how I can have faith in spite of this or that being "proven". I really feel like science is all about theories. Anything that science finds as fact will show there is a God. People who don't believe in God spend too much time in their own heads and not enough time in their hearts. All good things, and I really do mean all good things, bear witness of Him.
Evolution is a theory, it is not a fact. Man coming out of fish, or apes or anything else is a theory. You can't find a single thing in recent history that proves beyond any doubt that evolution is currently happening across species.
In order for us to believe anything, we have to think about it, then take it to heart. I believe because my heart and my head bear witness to me. I don't have to see all the facts in order to accept it. There was a time in my life when I wanted someone to tell me what was true. I wanted to understand all the mysteries. I wanted to know all the answers. And I wanted answers that could be irrevocably proven.
Here's the problem with that, faith can not be proven. That is why it is faith first. As things change, I believe that faith can become knowledge. But first, you have to believe. As I have gotten older, it is easier for me not to need all the proof that the world requires. I have learned the value of prayer and that answers do come with a still small voice and a burning in my heart. That is enough for me to keep the fire of belief kindled even when I don't know all the answers. Even when I lack certain proof.
As you struggle with your own questions and concerns, remember that faith in something comes long before knowledge. Just because we can't see in the darkness doesn't mean something isn't really there. I wish that I had the words to explain how deep the feelings run in my heart.
Instead of looking for reasons why you shouldn't have faith, maybe we should look for reasons why we should, maybe as we strengthen our faith we can overcome our unbelief. I love that Heavenly Father knew we would struggle with belief. He knew that it would sometimes, be seemingly impossible for us. And so He councils us to turn to Him. He shows us how to gain belief in our hearts.
Or, as the scriptures word it:
“Jesus said unto him, If thou canst believe, all things are possible to him that believeth.
“And straightway the father of the child cried out, and said with tears, Lord, I believe; help thou mine unbelief.”