Resurrection BaptismSome say that baptism is a symbol of salvation, and yet 1 Peter 3:21 says something else,

[T]he forbearance of God waited in the days of Noah building a ship unto which a few, these are eight souls were saved through water. This is also an antitype, baptism now saves us, not the removal of the filth of the flesh, but the request of a good conscience unto God, through the resurrection of Jesus Christ, (1 Pet 3:20–21).

What is an antitype? The word “antitype” is from the Greek antitupos. The Greek anti meaning “corresponding, similar, or like” to tupos meaning “form, model, example, or pattern (type).” Hebrews 9:24 speaks of the physical things and services of Israel’s temple, which are antitypes of the heavenly ones. Within context, 1 Peter 3:20 speaks of the antitype of eight persons being saved through the waters of the flood. This salvation through water is a similar example to baptism, because God saves believers through water. Noah’s salvation through water is a “like figure” to salvation through water. Noah’s family being saved from evil through water is a like-model of baptism in Jesus’s name when God saves believers from evil through water.

And with many other words he testified and exhorted them, saying, ‘Be saved from this perverse generation.Then those who gladly received his word were baptized; and that day about three thousand souls were added. (Acts 2:40–41; emp. added).

First Peter 3:21 specifically says in Greek that “baptism now saves us.” How? It is not the water that saves, but we are saved through water. It is written that Christ sanctifies and cleanses His Church “by the washing of water in the Word” (Eph 5:26). True believers are saved through water from a world a wickedness like Noah’s family was saved through water from a wicked world. Therefore, true believers are purified by our obedience in which we are born again.

Since you have purified your souls in obeying the truth through the Spirit in sincere love of the brethren, love one another fervently with a pure heart, having been born again, not of corruptible seed but incorruptible, through the word of God which lives and abides forever, (1 Pet 1:22–23)

Therefore, Christians are born again by obedience and purification. Peter revealed, “Blessed be the God and Father of our Lord Jesus Christ, who according to His abundant mercy has begotten us again to a living hope through the resurrection of Jesus Christ from the dead,” (1 Pet 1:3). Notice that we are begotten again, born again, “through the resurrection of Jesus Christ from the dead”, which is what we find about being saved by baptism in 1 Peter 3:21, “through the resurrection of Jesus Christ.” God raises Christians when each one has died to sins. First Peter 2:24 declares, “who Himself bore our sins in His own body on the tree, that we, having died to sins, might live for righteousness.” Baptism is the point of the Christian’s resurrection into the newness of life with Christ (1 Pet 3:21). Baptism is the burial of our sinful selves, which is the Gospel: the death, burial, and resurrection of Jesus Christ (1 Pet 3:18, cf. 1 Cor 15:1–4).

Read again, “[T]hese are eight souls were saved through water. This is also an antitype, baptism now saves us” (1 Pet 3:20b–21a). The corresponding example of Noah’s salvation through water is baptism by water in Jesus’s name that saves all, who truly believe.

Also see these articles from other Christian sources:

How to Be Saved
What is the Purpose of Baptism?
Please Explain 1 Peter 3:21