By this time John the Baptist had been imprisoned by Herod and was at the point of being executed. However, even John needed to know whether or not Jesus was the saviour to come. It is clear that Jesus had become well known for the many mighty works that he had done, and before him John was well known for his preaching to the people about a Christ who was to come. The word, Christ, means an anointed one.
The primary reason why John the Baptist arose was to bear testimony to the Christ who was to come and he needed to know for certain whether Jesus was the Christ or if there was another.
Now Jesus said that in the last days there would be many false prophets and false teachers who would claim to be the Christ. In Mark 13:5-6 he said, “And Jesus began to say to them, “Take heed that no one leads you astray. Many will come in my name, saying, ‘I am he!’ and they will lead many astray.” Now in the situation with John Jesus needed to provide proof of who he was and not simply tell John and his disciples that, “I am he” lest he be perceived to be one of these false ones.
So instead Jesus told John’s disciples to observe what he was doing. He said, “Go and tell John what you hear and see: the blind receive their sight and the lame walk, lepers are cleansed and the deaf hear, and the dead are raised up, and the poor have good news preached to them. And blessed is he who takes no offence at me.” (Verses 4-6) The proof he provided was not in his words but in his actions and deeds.
We see in other places when he talks of those who go about teaching and preaching that you will know them by their fruits. In Matthew 7:15-18 he said, “Beware of false prophets, who come to you in sheep’s clothing but inwardly are ravenous wolves. You will know them by their fruits. Are grapes gathered from thorns, or figs from thistles? So, every sound tree bears good fruit, but the bad tree bears evil fruit. A sound tree cannot bear evil fruit, nor can a bad tree bear good fruit.” Using this analogy we see a good tree, or a good teacher, will not give bad fruit or bad teaching. But a bad tree or a false teacher can only bear bad fruit or evil teachings.
It is by what they do that you can assess whether the person and their teachings are good or not. What we saw when John’s disciples came to him was Jesus applying this same principle to himself. If they saw good being done and the good word being taught they could be confident that he was the Christ. But if they perceived his actions to be of evil intent then they should report back to John that he was not the Christ.
This shows great wisdom and insight by the Lord for he used his own test that he gave us to determine good teaching from evil on himself. Needless to say the disciples reported back to John what they had seen Jesus do and teach and John was fully convinced that Jesus was the Christ. We see elsewhere that in this knowledge of Jesus as the Christ, John said that Jesus would grow while John would fade as he had done what he was meant to do. His words were, “He must increase, but I must decrease.” (John 3:30) And increase he did as he brought about the New Covenant by which all of mankind has the opportunity to be saved.