The word "baptism" was transliterated from the Greek. It is Strong's Gr. 908, "βάπτισμα", or "baptisma" and it means submersion, or immersion. The negative statement within the verse - "not the removal of dirt from the flesh" - confirms the act of a washing, but not for the purpose of bathing. So, this is immersion in water.
The word "baptisma" should have been translated for what it means - "immersion." But the 15th & 16th century English translators were afraid, and so they Anglicized the Greek word. If you say this word in Greece even today, the Greek people will understand its common meaning of submerging something most usually in water. It is the act of dunking completely under.
The early English translators avoided a political problem so as not to offend the religious leaders of the Catholic and Anglican churches, as well as the king of England, who had been taught to be "sprinkled" according to the teaching of the religious bishops and leaders of that time.
But, 1 Pet. 1:3 as well as every instance in the book of Acts makes it abundantly clear that immersion in water was the command to be born of the "water and the spirit."
"Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God." (John 3:5, KJV)
When you believe that Christ is the Son of YHVH, and when you have repented of your sins, the act of immersion in water is the answer of the good conscience to YHVH's call. It is our obedience to the command Christ gave everyone.
"He that believeth and is baptized shall be saved; but he that believeth not shall be damned." (Mark 16:16, KJV).
Correctly translated, it should read:
He that believeth and is immersed shall be saved; ....
This is what Annanias told Saul/Paul in Damascus.
"17 And Ananias went his way, and entered into the house; and putting his hands on him said, Brother Saul, the Lord, even Jesus, that appeared unto thee in the way as thou camest, hath sent me, that thou mightest receive thy sight, and be filled with the Holy Ghost.
18 And immediately there fell from his eyes as it had been scales: and he received sight forthwith, and arose, and was [immersed]." (Acts 9:17-18)
That is how Paul answered the call. That is still how we answer the call. Believing and being immersed. That is our new birth; when we are born of the water and the Spirit. The Holy Spirit then writes our name in the book of life (Phil. 4:3; Rev. 3:5; 13:8; 17:8; 20:12, 15. etc), and He does the work of covering / clothing us. That is when we are covered by Christ's blood (the symbol of the Passover, the blood of the lamb over the door) (Rom. 4:7), and clothed in His righteousness (Matt. 22:11-13).
The immersion does not work repentance. We are the ones who must first repent. The immersion cleanses us once we repent, and continues to cleanse as we ask for forgiveness and if we truly repent from then on. (This is not permission to sin, and then ask God to forgive as Paul makes clear in Rom. ch. 5-6).
We then rise up out of that water a new creature (2 Cor. 5:17; Eph 4:24; Col. 3:10), resurrected into eternal life. As long as we continue to walk after Christ, to walk in His Way, to repent of our sins asking for forgiveness as we make mistakes, and continue faithfully, then when we die we are taken up into heaven to be with the rest of the saved forever more (1 Thess. 4:17. Rev. 14:13)
Without the covering of His blood, His sin-offering, His clothing, His wedding garments, His righteousness - we will be lost. We are promised His covering when we are immersed in water - "baptized."
Here are the meanings of “baptizo” from reliable lexicons, as used in the original Koine (common) Greek at the time of Christ, in the first century A.D
Baptizo: “To make a thing dipped or dyed. To immerse for a religious purpose” (A Critical Lexicon and Concordance to the English and Greek New Testament, E.W. Bullinger).
Baptizo: “Dip, immerse, mid. Dip oneself, wash (in non-Christian lit. also ‘plunge, sink, drench, overwhelm. . . .’)” (A Greek-English Lexicon of the New Testament, Arndt and Gingrich, p. 131).
Baptizo: “immersion, submersion” (A Greek-English Lexicon of the New Testament, Grimm-Thayer, p. 94).
Baptizo: “to dip, immerse, sink” (Manual Greek Lexicon of the New Testament, Abbott-Smith, p. 74).
Baptizo: “dip, plunge” (A Greek-English Lexicon, Liddell & Scott, p. 305).
Baptizo: “consisting of the process of immersion, submersion and emergence (from bapto, to dip)” (Vine’s Expository Dictionary of New Testament Words).
Baptizo: “immerse, sumberge. The peculiar N.T. and Christian use of the word to denote immersion, submersion for a religious purpose” (Biblico-Theological Lexicon of the New Testament Greek, Cremer).
Baptizo: “to dip, immerse; to cleanse or purify by washing” (The New Analytical Greek Lexicon, Perschbacher, p. 66).
Baptizo: “to dip, to immerse, to sink. . . . There is no evidence that Luke or Paul and the other writers of the New Testament put upon this verb meanings not recognized by the Greeks” (Greek and English Lexicon, Sophocles).
The Greek word “baptizo” comes from the primary verb “bapto” which means to overwhelm, to cover wholly with a fluid.
Even the Roman Catholic Church knew the practice was immersion in water. This was not changed until the Council of Ravenna officially allowed sprinkling in 1311 AD. Surely our Lord and Savior, Christ the Son of God is sufficient example. He went to John to the river Jordan to be immersed in water for obedience to the Father in all things.
Another post you might enjoy, "Baptism - Transliteration, Translation and
See also the post at my site, "Do You Need to be Baptized to be Saved" ShreddingTheVeil and "The Thief On The Cross" here.