3:15-20 John the Baptist disowned being himself the Christ, but confirmed the people in their expectations of the long-promised Messiah. He could only exhort them to repent, and assure them of forgiveness upon repentance; but he could not work repentance in them, nor confer remission on them. Thus highly does it become us to speak of Christ, and thus humbly of ourselves. John can do no more than baptize with water, in token that they ought to purify and cleanse themselves; but Christ can, and will baptize with the Holy Ghost; he can give the Spirit, to cleanse and purify the heart, not only as water washes off the dirt on the outside, but as fire clears out the dross that is within, and melts down the metal, that it may be cast into a new mould. John was an affectionate preacher; he was beseeching; he pressed things home upon his hearers. He was a practical preacher; quickening them to their duty, and directing them in it. He was a popular preacher; he addressed the people, according to their capacity. He was an evangelical preacher. In all his exhortations, he directed people to Christ. When we press duty upon people, we must direct them to Christ, both for righteousness and strength. He was a copious preacher; he shunned not to declare the whole counsel of God. But a full stop was put to John's preaching when he was in the midst of his usefulness. Herod being reproved by him for many evils, shut up John in prison. Those who injure the faithful servants of God, add still greater guilt to their other sins.

15-17. whether he were the Christ—showing both how successful he had been in awakening the expectation of Messiah's immediate appearing, and the high estimation, and even reverence, which his own character commanded. (Also see on [1555]Mt 3:10.)