Baptism is simple but profound, and is essential for salvation. An adult who understands the gospel is immersed in water, signifying a “death”, and a rising to a new life following Jesus’ example.
Baptism is a symbolic act where a person is acknowledging they actually deserved the death Jesus suffered on account of their sins, but on the positive side, they want to change and live a new life like him from this point. (Romans 6)
God gives recognition to this act and on account of it will forgive sins and provide salvation.
Jesus himself was baptised, and requires his followers to do the same (Matthew 3:13-17). This act of baptism, followed by a life of discipleship, gives believers a hope of eternal life in the Kingdom of God (Mark 16:15-16)