Summary: Discusses baptism and then continues with the Remembrance that we are baptized ritual.
Over the centuries Christians have debated what baptism accomplishes, to whom it should be administered, and how much water should be used.
Christian Theology in Plain Language, p. 158.
The story is told about the baptism of King Aengus by St. Patrick in the middle of the fifth century. Sometime during the rite, St. Patrick leaned on his sharp-pointed staff and inadvertently stabbed the king's foot. After the baptism was over, St. Patrick looked down at all the blood, realized what he had done, and begged the king's forgiveness. Why did you suffer this pain in silence, the Saint wanted to know. The king replied, "I thought it was part of the ritual."
Baptism in those days could be for repentance or conversion. The Jews baptized or washed themselves to cleans themselves of sin as well as offering sacrifices according to the Law. Today, washing, I suppose we could compare it to coming to the Alter and cleansing ourselves through prayer and leaving the sin there. When a non Jew came to faith in the Jewish God they were baptized or washed to have them join with them.
John the Baptist was doing a different thing with this water baptism. He was asking them to repent and wash away their sins. He was actually turning them away if they didn't show fruits of their repentance. Calling them snakes and to get right with God first before you come to be washed or baptized. He didn't say go to the temple and offer an appropriate sacrifice according to the Law.
John the Baptist was moving away from the Law that made them realize they are sinners and not very pure at all. He was offering a way to be clean from sin and to be pure. With him it was showing proof of your changed life then you could come join him in being cleansed of your sins through washing or baptizing in water.
With this life style change you would join with the people with changed lives. Lives that pulled you to God Almighty.
We are born with a sin nature; that drawing towards doing sinful things. But Jesus didn’t have that sin nature within Himself. But he was tempted as we are and did not sin;
Hebrews 4:15 (ESV) Speaking of Jesus:
...but one who in every respect has been tempted as we are, yet without sin.
Since Jesus was truly God (Colossians 2:9) and truly human and our Holy Scriptures tell us he never sinned, Why would he come to be baptized?
Jesus did not need to be baptized with water for the remission of His sin.
-From Adam to Moses there were no written law for them to be accounted to except what was passed down from the Patriarchs.
-From Moses to John the Baptist there was the written law handed to Moses that showed them they could never be pure and never without sin. The animal sacrifices only covered their sin never rid them of it.
-From John the Baptist to Jesus there was an enlightenment of getting their life right and receiving the washing or baptism of remission of their sins through water.
-From Jesus until now we are to accept God through Jesus and be filled with the Holy Spirit just the way we are; sinful humans with that sinful nature we were borne with.