"I don’t think faith is positive, because faith means belief without evidence, and you shouldn’t believe anything without evidence. ["The Daily Show"… - Richard Dawkins

Religion is a distraction from true education.

It is absolutely safe to say that if you meet somebody who claims not to believe in evolution, that person is ignorant, stupid or insane (or wicked, but I'd rather not consider that).

Let children learn about different faiths, let them notice their incompatibility, and let them draw their own conclusions about the consequences of that incompatibility. As for whether they are ‘valid,’ let them make up their own minds when they are old enough to do so.