Then Philip opened his mouth, and beginning with this Scripture he told him the good news about Jesus. And as they were going along the road they came to some water, and the eunuch said, “See, here is water! What prevents me from being baptized?” And he commanded the chariot to stop, and they both went down into the water, Philip and the eunuch, and he baptized him. (Acts 8:35-38 ESV)
Baptism is a willing act of obedience from one who first accepts Jesus Christ as their personal Lord and Saviour. Mark 16:16 says to first believe; Acts 2:38 says to first repent; Acts 8:35-38 recounts that the eunuch was first preached the truth of Christ and through acceptance of the truth, was compelled to be baptized. Baptism is a desire from the believer to outwardly display the death of their old being and their new life in Christ.
Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death? We were buried therefore with him by baptism into death, in order that, just as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life.
For if we have been united with him in a death like his, we shall certainly be united with him in a resurrection like his. We know that our old self was crucified with him in order that the body of sin might be brought to nothing, so that we would no longer be enslaved to sin. (Romans 6:3-6 ESV)
Baptism is not mandatory for salvation. Look at the thief hanging on the cross along side Jesus (Luke 23:39-43). Did Jesus say to him “go find water to be baptized and you will be with me in heaven”? Salvation comes through Christ alone (John 14:6; Acts 4:12). Without first accepting Christ personally, baptism is nothing more than an empty act. However, for those who have accepted Christ as their Lord and Saviour, the desire to want to express their joy of being transformed in Christ through baptism is a wonderful gift God has blessed us with. Just like the eunuch in Acts 8, may those in Christ be grateful for the blessing of being able to outwardly show that Christ has redeemed us.