Do not waste time bothering whether you “love” your neighbor; act as if you did. As soon as we do this we find one of the great secrets. When you are behaving as if you loved someone you will presently come to love him.
We are told that Christ was killed for us, that His death has washed out our sins, and that by dying He disable death itself. That is the formula. That is Christianity. That is what has to be believed.