Actually, you’re misquoting scripture. Go back and read the whole passage before the verse you cherry pick; you can’t take the one verse and make it say what you want because you want it to say what you want.
Water baptism, in and of itself, cannot save. It’s not a contradiction. But you are misunderstanding it.
Hoss
No one said Baptism “in and of itself” saves.
But Baptism does save. That’s what Scripture says and that’s what Jesus commanded of us.