John the Baptist was sent in order to prepare the way for Christ. He drew a large crowd as he preached in the wilderness, with people coming from Jerusalem, Judea, and the district around the Jordan (Matthew 3:5).
His message called people to “repent” in anticipation of the coming kingdom (Matthew 3:2). Those who responded to his teaching “were being baptized…as they confessed their sins” (Matthew 3:6).
However, when the Pharisees and Sadducees came to him, he called them a “brood of vipers” and warned them that “the axe [was] already laid at the root of the trees” (Matthew 3:7, 10), signifying the divine judgment that was coming against them. So he told them to “bear fruit in keeping with repentance” (Matthew 3:8).
This is an important point for us to remember. Even today, God calls people to repent and turn to Him (cf. Acts 17:30). Yet repentance, like faith, must be demonstrated by our actions (cf. James 2:17). It is not enough to say we are turning to the Lord. We need to change our behavior and conform our lives to His will.
So bear fruit in keeping with repentance. Following Christ means that our lives must be different from the world around us. If we want to please the Lord, we cannot continue to live as we did before choosing to follow Him.