'Baptism' in the Bible

And he came into all the region round about the Jordan, preaching the baptism of repentance unto remission of sins;

And all the people when they heard, and the publicans, justified God, being baptized with the baptism of John.

But I have a baptism to be baptized with; and how am I straitened till it be accomplished!

The baptism of John, was it from heaven, or from men?