Mark 1:9

And it came to pass in those days, that Jesus came from Nazareth of Galilee, and was baptized of John in the Jordan. And straightway coming up out of the water, he saw the heavens rent asunder, and the Spirit as a dove descending upon him: and a voice from out of the heavens, Thou art my beloved Son, in whom I am well pleased.

Mark's account of the baptism of Jesus gives far less detail than Matthew, omitting the reluctance of John to baptize him and Jesus' statement of his purpose in it. Jesus was about thirty years of age when this event occurred (Luke 3:23).

In the Jordan ... The baptism administered by John, and later that by the apostles, required that it be done "in" water, not merely "with" water, showing that immersion was the action called baptism.

And straightway coming up out of the water ... Here is Mark's first use of "straightway," one of his favorite expressions, which recurs many times in this gospel. "Out of the water ..." indicates that Jesus was immersed; and, if such was not the case, there could have been no reason whatever for his coming "up out of the water." If any other "form" of baptism had been in vogue, neither Jesus nor John would have been in the water at all.

Spirit as a dove ... The significance of this lies in the Spirit's choice of such a symbol of himself, the dove being associated with certain religious sacrifices, having been the messenger of hope for Noah, and a symbol of peace and gentleness in all ages. This was the sign by which John the Baptist recognized the Messiah (John 1:32).

And a voice out of the heavens ... It will be noted that Mark's account makes the voice out of heaven to have been addressed directly to Jesus, "Thou art my beloved Son," whereas in Matthew it was stated generally, "This is my beloved Son." This is called a contradiction by some; but when it is recalled that each of the sacred writers reported in his own words what happened, such allegations are unjustified. As Halley said:

It is surprising with what utter abandon the statement is made in many present-day scholarly works that the Four Gospels are "full of contradictions." Then when we see the things that are called contradictions, we are almost tempted to lose respect for some of the so-called scholarship. The fact of different details and slight variations in describing the same incident makes the testimony of the various writers all the more trustworthy, for it precludes the possibility of pre-arranged collusion among them[3]

Alleged contradictions in the New Testament deserve designation as PSEUDOCONS, a fabricated word derived from "pseudo," meaning "sham" or pretended, and "con," the first syllable of "contradiction." In this instance of it, Matthew reported the voice from heaven from the standpoint of John the Baptist, and Mark from the standpoint of Jesus, the latter being proved by the fact that John the Baptist's words were not mentioned by Mark. If he had reported the conversation of the herald, as did Matthew, he would necessarily have reported the voice as saying, "This is my beloved Son," in order to avoid leaving the impression that this was said of John the Baptist.