A friend of mine who is coming to know Jesus asked me the other day what he had to do to show that he is a Christian. I told him he had to do nothing, because faith saves us. Faith is that “yes” that wells in the human heart to God who is calling us. It is not something we do, but something that wells up inside and we respond to. Genuine faith of course leads to actions that spring forth from it (e.g. James 2:17; Gal 5:6; Eph 2:10); but it is the faith that saves us. We are “justified by faith” and not any works (see esp. Eph 2:8–9). That is the wonder of Christian salvation—Jesus has done it all for us, all we have to do is yield to him. When we do we are saved not by works, but by grace through faith alone.
However, while it is true that we are saved by faith alone, I suggested that baptism is the moment where we publically declare that faith to God and people. While some traditions sprinkle water for baptism, most do so by immersion—a person enters water, is immersed under it, and rises out of it.
This is the ritual that kind of ratifies our faith commitment. Just as marriage publically celebrates the coming together of a man and woman, so baptism marks the entry of a new convert into the church and union with God. One is no longer a de facto Christian, one is a full member of the church, the bride of Christ (Eph 5:25; Rev 19:7; 21:2), and part of the people now “married” to Christ and God (so to speak). Being baptised then is a statement to God, to the church, and to the world that one has “decided to follow Jesus,” as the ol’ hymn says.
In Acts in particular, we see that new converts were quickly baptised after conversion (Acts 8:12, 13, 16, 36, 38; 9:18; 10:48; 16:15, 33; 18:8; 19:5; 22:16). It is commanded that new converts should be baptized (e.g. Acts 2:38, 41). This is seen in the Great Commission in which Christians are commanded to go to all nations and make disciples. Such disciples are to be well educated in Jesus’ teaching and baptised in the name of the Father, the Son, and the Holy Spirit (Matt 28:19).
Christian baptism is not something new; it stands in continuity with Jewish ritual cleansing which a new convert went through along with circumcision. The prophet John the Baptist baptized people in this Jewish way, in preparation for the one “who would baptize with the Holy Spirit and fire” (Luke 3:16). His was a baptism of repentance (Mark 1:4). It was a kind of initiation into a “new Israel” in preparation for its Messiah.
In Christian thought, baptism is the ritual of initiation. When someone is baptized, the visual ritual declares and enacts that person’s identification with the death, burial, and resurrection of Christ. This is the event that saves us and we identify and participate spiritually in it. The baptisee goes under the water enacting the death and burial of Christ. They come up from the water symbolising their resurrection to new life (Rom 6:3–4; Col 2:12). Baptism enacts a new birth, our adoption as children, a believer is born again from above, they are regenerated (John 3:3–6; Tit 3:5; Rom 8:15; Gal 4:5). Baptism marks a believers’ expiation, their forgiveness or cleansing from sin (Acts 2:38; 22:16; 1 Cor 6:11; Tit 3:5). It marks the receipt of the Spirit, the baptism in the Spirit (Acts 2:38). It marks their entry into the church universal (all believers over time and across the world) and local (a local church community) (1 Cor 12:13).
Baptism is a vital moment in the life of a new believer. It kind of ratifies to everyone involved that this person is now God’s child. Others who are Christians witness this event and the person is incorporated into the body of Christ. God sees the act of commitment and faith, and is well pleased----the new birth of another of his children is celebrated.
As such, we should all be baptised when we come to faith in Jesus. It is an important moment in our lives which confirms that we are truly believers, a child of God, born again, destined for salvation, and part of God’s great family that spans history and all peoples. It is a glorious moment when the angels rejoice that someone else will get to live with God forever.
Of course if we are from a paedo-baptist tradition, then this is a little more complicated. Confirmation traditionally plays the role in such churches whereby a person baptised as an infant has a confirmation ceremony, which “confirms” their commitment to God. Some have a reaffirmation of the earlier baptism with the adult believer being immersed. This is not a rebaptism, but a reaffirmation. Others do not take seriously paedo-baptism at all, consider it worthless, and endorse a second baptism. All these things get a little detailed and confused. Personally, I think that point of faith-commitment is best followed by being immersed. Whether it is a reaffirmation or baptism itself is neither here nor there; it is just theologising and I am not sure God is that concerned. What matters is that we publically mark our confession of faith.
So, it is good to be baptised (or confirmed). It is an act of obedience. It marks our inclusion in Christ, our cleansing, our initiation into the faith and church. It makes public and real our acceptance of God's invitation to salvation. It is like a marriage ceremony. We are included in God's people.