What is Baptism?
Baptism is the outward expression of a believer's inner faith. It does not save the person. Only his faith in Christ can do that. It is like a wedding ring. The wedding ring is the outward symbol of a person's commitment to the vows he has taken. But wearing a wedding ring doesn't make a person married. It is only a visible sign of what has already been done. Baptism in water is like that. It is the outward symbol of the commitment a believer has already made to receive Christ as his Lord and Saviour.
a. Symbol of a believer's identification with the death, burial and resurrection of Christ
"Or don't you know that all of us who were baptized into Christ Jesus were baptized into his death? 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." (Romans 6:3-4)
When a believer is submerged in the water, it symbolises death and burial of his old sinful self. When the believer emerges from the water, he no longer serves the sinful nature and is freed from sin's power over him
b. Public declaration of a believer's union and new identity in Christ
i. The believer's union and new identity in Christ
Peter replied, "Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins. And you will receive the gift of the Holy Spirit.”(Acts 2:38)
When a believer gets baptised before his loved ones and friends, he is publicly expressing that he has entered into a new covenant relationship with Jesus Christ, who is now his Lord and Saviour. He is now a new creation and his old way has passed away.
ii. The believer's new life
"Therefore, if anyone is in Christ, he is a new creation; the old has gone, the new has come!" (2 Corinthians 5:17)
c. Expression of a believer's identification with the Body of Christ
To enter into a relationship with Christ involves becoming part of His Body, the Church. Water baptism also symbolises the believer's identification with a local church.
"For we were all baptized by one Spirit into one body – whether Jews or Greeks, slave or free – and we were all given the one Spirit to drink." (1 Corinthians 12:13)