I may be getting into something here that I am not sure of, but I will make a stab at it. I believe if, say for instance you, (that is what we are talking about right) You are not sure but you think it may be true that Jesus is God incarnate come to save the lost by His sacrifice. I believe if by faith you act on that even if you have doubts (which BTW, we all do at times, that is Satan), and continue by faith to act on God's promises He will increase your beliefs and give you peace about it. Acting on faith would be to continue to study His Word and accept it by faith.
Roms. 10:17 So then faith cometh by hearing and hearing by the Word of God.
Becky