Everyone doubts

Blind faith is really not faith at all. To strengthen faith you have to test it, question it, and delve into it. It is easy to believe something, but that could mean nothing in terms of life change. You must make your faith a part of your life, not just another fact stored in your head. This is true with everything, not just religious faith. You could have faith in a friend, but doing this blindly will result in a lack of true trust.