One of the Apostolic teachings that have impressed me very much recently is that of Repentance and Baptism in the Name of Yeshua (Iesous) the Anointed One.
Acts 2:38
"Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost."
The Apostles had always taught repentance and baptism.
The call to repent and to be washed in the waters of baptism is an ancient Jewish practice called respectively "teshuva and mikveh" in Hebrew. I'm persuaded that when Peter told the crowd in Jerusalem to "Repent and be baptized" that Pentecost (Shavuot) day, his audience was not surprised by anything new. It was just a call to "teshuva and mikveh".
In Jewish teaching, baptism is effective only if one sets his heart on becoming pure. It is highly likely that Peter's call to repentance and baptism was made in the same context too. The only big difference was the mikveh was to be performed by calling upon the Name of the Messiah - Yeshua.
The following is an excerpt from "The Dynamics of Teshuva" in the book "Deep Calling Unto Deep" published by Kehot Publication Society, 770 Eastern Parkway, Brooklyn, NY 11213, authored by Dr. J. Immanuel Schochet, Professor of Philosophy at Humber College, Toronto, Ontario, Canada.
"Just as sin is rooted in man's will and mind, so must teshuvah be rooted in man's will and mind. . . .He who sets his heart on becoming purified (from ritual defilement) becomes pure as soon as he has immersed himself (in the waters of a mikveh), though nothing new has befallen his body. So, too, it is with one who sets his heart on cleansing himself from the impurities that beset man's soul - namely, wrongful thoughts and false convictions: as soon as he consents in his heart to withdraw from those counsels and brings his soul into the waters of reason, he is pure."
