Does Baptism Really Save You?

I’ve been studying the Bible with a group of self-righteous people, and they strongly believe that baptism—full immersion in water—is 100% necessary for salvation. They say that even if I’m the best person, without baptism, I’m not saved.

I’m trying to understand this better. I know verses like Mark 16:16 and Acts 2:38 emphasize baptism, but what about faith and grace? Ephesians 2:8-9 talks about being saved by grace through faith, not works.

Is baptism a requirement for salvation, or is it more of an outward sign of an inward faith? I’d love to hear different perspectives—especially biblical ones!