<P> The Christian rite of baptism has similarities to Tevilah, a Jewish purification ritual of immersing in water which is required for, among other things, conversion, but differs in that Tevilah is repeatable, while baptism is to be performed only once . John the Baptist, who is considered a forerunner to Christianity, used baptism as the central sacrament of his messianic movement . Christians consider Jesus to have instituted the sacrament of baptism . The earliest Christian baptisms were probably normally by immersion, though other modes may have also been used . By the third and fourth centuries, baptism involved catechetical instruction as well as chrismation, exorcisms, laying on of hands, and recitation of a creed . Affusion became the normal mode of baptism between the twelfth and fourteenth centuries, though immersion was still practiced into the sixteenth . In the sixteenth century, Martin Luther retained baptism as a sacrament, but Swiss reformer Huldrych Zwingli considered baptism and the Lord's supper to be symbolic . Anabaptists denied the validity of infant baptism, which was the normal practice when their movement started and practiced believer's baptism instead . Several other groups, notably the Baptists and Dunkards, have always practiced baptism by immersion as following the Biblical example . </P> <P> Although the term "baptism" is not used to describe the Jewish rituals, the purification rites in Jewish laws and tradition, called "Tvilah", have some similarity to baptism, and the two have been linked . The "Tvilah" is the act of immersion in natural sourced water, called a "Mikva" In the Jewish Bible and other Jewish texts, immersion in water for ritual purification was established for restoration to a condition of "ritual purity" in specific circumstances . For example, Jews who (according to the Law of Moses) became ritually defiled by contact with a corpse had to use the mikvah before being allowed to participate in the Holy Temple . Immersion is required for converts to Judaism as part of their conversion . Immersion in the mikvah represents a change in status in regards to purification, restoration, and qualification for full religious participation in the life of the community, ensuring that the cleansed person will not impose uncleanness on property or its owners . It did not become customary, however, to immerse converts to Judaism until after the Babylonian Captivity . This change of status by the mikvah could be obtained repeatedly, while Christian baptism, like circumcision, is, in the general view of Christians, unique and not repeatable . Even the so - called rebaptism by some Christian denominations is not seen by them as a repetition of an earlier valid baptism and is viewed by them as not itself repeatable . </P>

Where did the practice of baptism come from