We get baptize to wash away sins. If Jesus is without sin, why did he get baptized?
"Then Jesus came from Galilee to John at the Jordan to be baptized by him. And John tried to prevent Him, saying, "I need to be baptized by You, and are You coming to me?" But Jesus answered and said to him, "Permit it to be so now, for thus it is fitting for us to fulfill all righteousness." Then he allowed Him. When He had been baptized, Jesus came up immediately from the water; and behold, the heavens were opened to Him, and He saw the Spirit of God descending like a dove and alighting upon Him. And suddenly a voice came from heaven, saying, "This is My beloved Son, in whom I am well pleased"" (Matthew 3:13-17).
John recognized that Jesus was sinless and he was not. He objected to Jesus' request to be baptized because of this. But Jesus told it was needed to be done to fulfill all righteousness. In other words, baptism was a command of God. Even though Jesus had no sins to wash away, the command to be baptized remained and as an obedient Son, Jesus was baptized.
This becomes another flaw in the usual arguments that baptism is not necessary. Even it if didn't have anything to do with removing sins (and it does -- Acts 22:16), it still remains necessary because it is a command of God.