Jesus had to fulfill God’s mission which meant fulfilling all righteousness. In order to accomplish the mission, Jesus was baptized in the River Jordan by John.

¹³Then Jesus came from Galilee to the Jordan to John, to be baptized by him. ¹⁴John would have prevented him, saying, “I need to be baptized by you, and do you come to me?” ¹⁵But Jesus answered him, “Let it be so now, for thus it is fitting for us to fulfill all righteousness.” Then he consented. ¹⁶And when Jesus was baptized, immediately he went up from the water, and behold, the heavens were opened to him, and he saw the Spirit of God descending like a dove and coming to rest on him; ¹⁷