'Baptism' in the Bible

So John the Baptizer came, and was in the Desert proclaiming a baptism of the penitent for forgiveness of sins.

"You know not," said He, "what you are asking. Are you able to drink out of the cup from which I am to drink, or to be baptized with the baptism with which I am to be baptized?"

"We are able," they replied. "Out of the cup," said Jesus, "from which I am to drink you shall drink, and with the baptism with which I am to be baptized you shall be baptized;

John's Baptism--was it of Heavenly or of human origin? Answer me."