(1.) It is dated by the reign of the Roman emperor; it was in the fifteenth year of Tiberius Cæsar, the third of the twelve Cæsars, a very bad man, given to covetousness, drunkenness, and cruelty; such a man is mentioned first (saith Dr. Lightfoot), as it were, to teach us what to look for from that cruel and abominable city wherein Satan reigned in all ages and successions. The people of the Jews, after a long struggle, were of late made a province of the empire, and were under the dominion of this Tiberius; and that country which once had made so great a figure, and had many nations tributaries to it, in the reigns of David and Solomon, is now itself an inconsiderable despicable part of the Roman empire, and rather trampled upon than triumphed in.

Matthew Henry Commentary on the Whole Bible (Concise) (Matthew Henry)

Verses 1-14 The scope and design of John's ministry were, to bring the people from their sins, and to their Saviour. He came preaching, not a sect, or party, but a profession; the sign or ceremony was washing with water. By the words here used John preached the necessity of repentance, in order to the remission of sins, and that the baptism of water was an outward sign of that inward cleansing and renewal of heart, which attend, or are the effects of true repentance, as well as a profession of it. Here is the fulfilling of the Scriptures, ( Isaiah 40:3 ) , in the ministry of John. When way is made for the gospel into the heart, by taking down high thoughts, and bringing them into obedience to Christ, by levelling the soul, and removing all that hinders us in the way of Christ and his grace, then preparation is made to welcome the salvation of God. Here are general warnings and exhortations which John gave. The guilty, corrupted race of mankind is become a generation of vipers; hateful to God, and hating one another. There is no way of fleeing from the wrath to come, but by repentance; and by the change of our way the change of our mind must be shown. If we are not really holy, both in heart and life, our profession of religion and relation to God and his church, will stand us in no stead at all; the sorer will our destruction be, if we do not bring forth fruits meet for repentance. John the Baptist gave instructions to several sorts of persons. Those that profess and promise repentance, must show it by reformation, according to their places and conditions. The gospel requires mercy, not sacrifice; and its design is, to engage us to do all the good we can, and to be just to all men. And the same principle which leads men to forego unjust gain, leads to restore that which…