John the Baptist is challenging his fellow Jews to take a serious look at their sin. Jews typically behaved much better than their non-Jewish neighbors, so they probably thought they were doing pretty well. John lets them know God’s kingdom is coming, and the half-hearted attempts at living life like they should were not going to be enough. They needed to be cleansed from sin in a way only God could provide. Even though Jesus had no sin that required repentance or cleansing, he still wanted to be baptized to show that cleansing from God was necessary to achieve righteousness from God’s perspective.
Do you rely on your own good behavior to achieve righteousness or the cleansing that comes from trusting in Jesus? If you are trusting in Jesus, have you been baptized to demonstrate that to others?