And thou, child, etc. - Zacharias proclaims the dignity, employment, doctrine, and success of his son; and the ruin and recovery of the Jews and the Gentiles.
- His dignity. Thou shalt be called (constituted) a prophet of the Most High. Prophet has two acceptations: -
1st. A person who foretells future events; and;
2dly. A teacher of men in the things of God, 1 Corinthians 14:3 .
John was a prophet in both senses: he proclaimed the mercy which should be communicated; announced the baptism of the Holy Spirit; and taught men how to leave their sins, and how to find the salvation of God. See Luke 3:5-14 . His very name, Jehochanan, the grace or mercy of Jehovah, (see Luke 1:60 ;), was a constant prediction of the salvation of God. Our Lord terms him the greatest prophet which had ever appeared in the world. He had the honor of being the last and clearest prophet of the old covenant, and the first of the new.
His employment. Thou shalt go before the face of the Lord to prepare his ways. He should be the immediate forerunner of Jesus Christ, none being capable of succeeding him in his ministry but Christ himself. He was to prepare his ways, to be the honored instrument, in the hands of God, of disposing the hearts of multitudes of the Israelites to believe in and follow the Lord Jesus. Zacharias points out the doctrine or teaching of John. It should be γνωσις σωτηριας , the science of salvation. Men are ignorant, and they must be instructed. Human sciences may be profitable in earthly matters, but cannot profit the soul. The science that teaches God must come from God. No science is of any avail to the soul that does not bring salvation with it: this is the excellence of heavenly science, and an excellence that is peculiar to itself. No science but that which comes from God can ever save a soul from the power, the guilt, and the pollution of sin. Zacharias predicts the success of his son's ministry. Under his preaching, the people should be directed to that tender mercy of God, through which they might obtain the remission of their sins, Luke 1:77 , Luke 1:78 . Those who are sent by God, and preach his truth, and his only, shall always be successful in their work; for it is for this very purpose that God has sent them; and it would be a marvelous thing, indeed, should they labor in vain. But there never was such a case, since God made man, in which a preacher was Divinely commissioned to preach Jesus and his salvation, and yet had no fruit of his labor. Zacharias points out the wretched state in which the inhabitants of Judea and the Gentile world were then found. 
