Luke 3: 12 Then tax collectors also came to be baptized, and said to him, “Teacher, what shall we do?”13 And he said to them, “Collect no more than what is appointed for you.”14 Likewise the soldiers asked him, saying, “And what shall we do?”So he said to them, “Do not intimidate anyone or accuse falsely, and be content with your wages.”15 Now as the people were in expectation, and all reasoned in their hearts about John, whether he was the Christ or not, 16 John answered, saying to all, “I indeed baptize you with water; but One mightier than I is coming, whose sandal strap I am not worthy to loose. He will baptize you with the Holy Spirit and fire. 17 His winnowing fan is in His hand, and He will thoroughly clean out His threshing floor, and gather the wheat into His barn; but the chaff He will burn with unquenchable fire.”18 And with many other exhortations he preached to the people. 19 But Herod the tetrarch, being rebuked by him concerning Herodias, his brother Philip’s wife, and for all the evils which Herod had done, 20 also added this, above all, that he shut John up in prison.21 When all the people were baptized, it came to pass that Jesus also was baptized; and while He prayed, the heaven was opened. 22 And the Holy Spirit descended in bodily form like a dove upon Him, and a voice came from heaven which said, “You are My beloved Son; in You I am well pleased.”

John saw into the secrets of the heart; but let us remember by whose grace, for it is of the gift of God to reveal things to man, not of the virtue of man, which is assisted by the Divine blessing, rather than capable of perceiving by any natural power of its own. But quickly answering them, he proved that he was not the Christ, for his works were by visible operations. For as man is compounded of two natures, i. e. soul and body, the visible mystery is made holy by the visible, the invisible by the invisible; for by water the body is washed, by the Spirit the soul is cleansed of its stains. It is permitted to us also in the very water to have the sanctifying influence of the Deity breathed upon us. And therefore there was one baptism of repentance,

(St Ambrose)