Mar 1:9 ¶ And it came to pass in those days, that Jesus came from Nazareth of Galilee, and was baptized of John in Jordan.
Mar 1:10 And straightway coming up out of the water, he saw the heavens opened, and the Spirit like a dove descending upon him:
Mar 1:11 And there came a voice from heaven, [saying], Thou art my beloved Son, in whom I am well pleased.
The Baptism was a testimony, the dove was a testimony and the voice was a testimony.