The word "baptize" or "baptized" is an Anglicized version of the Greek "baptizo", and is transliterated instead of being translated. The practice of immersion in water existed for centuries before it began to be altered as early as the 4th century AD, and being more commonly replaced by sprinkling in the 7th century AD. It is said that Eusebius “baptized” Emperor Constantine on his deathbed in 337 A.D. by pouring water over him.
“Sprinkling as a form of baptism took the place of immersion after a few centuries in the early Church, not from any established rule, but by common consent, and it has since been very generally practiced in all but the Greek and Baptist churches, which insist upon immersion.” (McClintock and Strong’s Cyclopedia, Art. Sprinkling, Vol. IX, p. 968).
"Sprinkling was still (in the period of 323 – 692) confined to Baptismus Clinicorum (clinical baptism) and was first generally used in the West in infant baptism in the 12th century, while the East still retained the custom of immersion.” (Kurts, a German Lutheran Historian, in Church History, Vol. I, p. 367)
The Catholic Church officially changed the form of baptism from immersion to sprinkling at the Council of Ravena in 1311 AD. (Notes 1, 2)
The reason we are stuck in continued arguments about what constitutes “baptism” with the denominational world is that the translators from the original Greek texts were afraid of offending the king. By the time the Bible was translated into the English in the 14th and 16th centuries A.D., too many powerful people, such as King James, had already been sprinkled under the practice of the Church of England as learned and approved from the Roman Catholic Church.
The word in the Greek means to be submerged or immersed. If you speak that word today in a Greek country they will understand it to be dunked, submerged, dipped under completely.
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
“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).
“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).
“immersion, submersion” (A Greek-English Lexicon of the New Testament, Grimm-Thayer, p. 94).
“to dip, immerse, sink” (Manual Greek Lexicon of the New Testament, Abbott-Smith, p. 74).
“dip, plunge” (A Greek-English Lexicon, Liddell & Scott, p. 305).
“consisting of the process of immersion, submersion and emergence (from bapto, to dip)” (Vine’s Expository Dictionary of New Testament Words).
“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).
“to dip, immerse; to cleanse or purify by washing” (The New Analytical Greek Lexicon, Perschbacher, p. 66).
“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.
F.H. Chase explains,
“In English we translate the Greek word baptizein. When we use the word “baptize” we think at once and we think only of the religious rite. Apart from that rite the word has no meaning for us. It is simply and solely a religious technical term. But the Aramaic Christian when he used the Aramaic word, and the Greek Christian when he used the Greek word, would never in this particular application of the term lose sight of its primary and proper signification “to immerse,” “to plunge in or into”,
and he continues
“In their versions of the New Testament the Syriac and the Egyptian Christians translated the word baptizein. Latin-speaking Christians, though like ourselves they commonly transliterated it (baptizare), yet sometimes . . . used as its equivalent the Latin verb tingere. What if we dare to follow their example and, instead of transliterating it, venture to translate it—Baptizontes autous eis to onoma, “immersing them into the Name”? So surely a Greek-speaking Christian would understand the words. He would regard the divine Name as the element, so to speak, into which the baptized is plunged. Thus the outward rite is seen to be an immediate parable of a great spiritual reality. (“The Lord’s Command to Baptize,” The Journal of Theological Studies, July, 1905, p. 503). (Bold emphasis is mine.)
The purpose of the immersion is the participation in the death, burial, and resurrection of Christ. It is an outward sign of an inward renewal, an inward decision to live for Christ, and follow Him. Sprinkling is not a burial into Christ’s death, burial, and resurrection. (Col. 2:12, Rom. 6:3-4; 2Cor 4:10-16)
1) Baptism changed from immersion to sprinkling in 1311 AD here
2) How Sprinkling or Pouring Replaced Scriptural Baptism here