Water is a symbol of cleansing (physical and religious). Almost all of the religions of the world has some sort of washing as a part of their rituals. Judaism was no exception as they had many ceremonial washings as part of the Jewish culture. Christianity is no exception as we have the water baptism whether it is sprinkling or immersion.
As Jesus addressed (even violated) many religious rituals, He did not leave the 'washings' away.
38But the Pharisee, noticing that Jesus did not first wash before the meal, was surprised. (Luke 11)
He did not wash before the meal(a Jewish custom) because He wanted to address the truth that the 'outward' washing means nothing if the 'inward' washing hasn't been taken place.
The inward washing of a man is done with the blood of the Lamb of God when he places his trust on Jesus. Once he is washed, his sinful nature is washed away. He is a new creation, a new self, child of the Almighty God.
This is the washing that God cares for. Whether we are outwardly washed (E.G baptism) or not means nothing if the inward washing hasn't been taken place.
So many people get hung up on baptism, communion etc where they miss the real thing, even those who sing - What can wash away my sin? Nothing but the blood of Jesus; What can make me whole again? Nothing but the blood of Jesus.