Jesus was a prophet as much as a priest and a king.
This three-fold ministry is on full display for us throughout the Gospels.
In the Sermon on the Mount, Jesus was very much the prophet, telling those who were listening what they would become by grace through faith -- preaching the coming of the Kingdom of God.
He had another vital ministry, one which brought the law back to its full, and unassailable height.
The Bible readers today must keep in mind that there are three distinct "races" to God: Jews, Gentiles, and the adopted children of God through Christ.
The Jews were God's chosen people, a peculiar people who were chosen not because of their great size, but because of their small number. From the beginning to the present day, God is looking for people who are nothing in themselves, and all in Christ.
"If ye then be risen with Christ, seek those things which are above, where Christ
sitteth on the right hand of God. 2Set your affection
on things above, not on things on the earth. 3For ye are dead,
and your life is hid with Christ in God. 4When Christ, who
is our life, shall appear, then shall ye also appear with him in glory." (Colossians 3: 1-4)
The Sermon on the Mount fits within one of two lines of prophecy:
1. To bring the Mosaic Law back to its pristine height, so that the Jewish people of His day would cease feigning and claiming righteousness in their ethnicity or in their efforts.
2. To preach the Kingdom of God, that by grace through faith you may be saved, passing from death into life.