Very simply, baptism is an outward testimony of the inward change in a believer’s life. Christian baptism is one of two ordinances that Jesus instituted for the church. Just before His ascension, Jesus said:

“Go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age.”

Matthew 29:19-20.

Christian baptism is the means by which a person makes a public profession of faith and discipleship. In the waters of baptism, a person says, wordlessly:

“I confess faith in Christ; Jesus has cleansed my soul from sin, and I now have a new life of sanctification.”

Colossians 2:12 states that being submerged in the water represents death to sin, and emerging from the water represents the cleansed, holy life that follows salvation. Romans 6:4 puts it this way:

“We were therefore buried with him through baptism into death in order that, just as Christ was raised from the dead through the glory of the Father, we too may live a new life.”