Baptism is administered to believers as a declaration of their faith in Jesus as Savior; telling the world they are truly his followers (Matthew 10:32).
Baptism doesn’t make you a believer; it shows that you already are one. The act of baptism isn’t what saves you. Only faith in Christ does that (Ephesians 2:8-9). Baptism is symbolic – an outward act of an inward spiritual change that has already taken place.