Paul explained the process and the meaning of baptism:
– Going under water symbolizes the death of our sinful bodies.
– Raising up from the water symbolizes the resurrection of our new bodies dedicated for God.
Overall, the public baptism is an example of what happens spiritually when we get saved (or repent).
Paul explained that non-believers (or sinners) are the servants of sin and/or devil and will be punished by death, but believers in Jesus Christ are made free from sin and from the law, and are the servants of God, or righteousness, and of obedience, and will be rewarded with an everlasting life with God.