"Many... said, John did no miracle: but all things that John spake of this man were true. And many believed on Him there." John 10:41, 42.
John did no miracle. In this respect his life was quite commonplace. But he said many things that were true about Christ. He said (and his whole life was behind his words), "Behold the Lamb of God."
Here, when John is off the scene, the people are face to face with the One he had witnessed to, and are constrained to say, "All things that John spake of this man were true." The result? "Many believed on Him there."
We are prone to depend on the unusual, the spectacular and the miraculous for the results we seek! Is it not, after all, more often the simple testimony of souls in love with Christ and on fire for Him that God uses?