Why Is Infant Baptism Not Necessary?

Tertullian says baptism seems like an easy, basic thing. He's trying to make arguments that you don't need to do all this preparation. His argument is a that, hey, god is going to be really harsh because he does have a pretty harsh view of god in general. But he doesn't say that infant baptism is invalid. And he's not saying, this is not valid baptism. Because of his moral rigor, he think he should wait.