What the Bible says about Progression Toward Kingdom of God
(From Forerunner Commentary)
John the Baptist came in the way of righteousness. He is not talking about just the instruction of righteousness. When the Bible speaks about a way, it is speaking about a walk, specifically the walk toward the Kingdom of God, that is, a set of behaviors that show progression toward the Kingdom of God. Jesus is saying that when John came, he did all these righteous acts that people could see. The Pharisees did not believe that the things John did was the way of righteousness, but He says here that the tax collectors and harlots did see them in Jesus, and they followed Him. They believed and began doing the things He was teaching and doing as an example of behavior.
Richard T. Ritenbaugh
Those Who Hunger and Thirst