Forgive me if someone else said this before.
But, -seriously.
"Believing" in the theory of evolution is unreasonable, not to mention an insult to what it truly is; a scientific model that attempts to explain the worldly phenomena we see around us. Science is not a faith, and every dipshit that claims that the theory of evolution (see? it's not a law) should be believed in, is kicking proper empirical science in the nutsack.
Scientific models try to make sense of worldly phenomena, so that we may interpret and predict them. Think of the two contradictory theories of interpreting light - particle and wave. Neither of them are probably 100% true, but both help us to predict and calculate the behavior of light and lasers to a degree that it allows us to erect technological progress around it.
Any -real- scientist will acknowledge that if a better model to explain the differentiation between (and development of) the species will pop up, the theory of evolution will be rightfully binned. Science isn't certain about evolution, it's just the best guess they have so far.