Jesus once testified of John the Baptist that he was the greatest man ever born, and so for him to preach the word of God would have been something, but Jesus spoke of something greater than John,

[John] was the burning and shining lamp, and you were willing for a time to rejoice in his light. But I have a greater witness than John’s; for the works which the Father has given Me to finish—the very works that I do—bear witness of Me, that the Father has sent Me” (John 5:35–36).

John identified Jesus as the Lamb of God, but the witness of the Father, which is greater than John’s, testified that He had sent Jesus into the world.

Let us rejoice in the preaching of John, but let us rejoice even more in the wonderful works that Jesus performed by the power and authority of the Father.