Here is John Wesley on the purpose of the Sermon on the Mount:
The Son of God, who came from heaven, is here showing us the way to heaven; to the place which he hath prepared for us; the glory he had before the world began. He is teaching us the true way to life everlasting; the royal way which leads to the kingdom; and the only true way, — for there is none besides; all other paths lead to destruction.
This description, of course, is a scandal to 21st century theology and biblical studies. It is, however, part of the doctrinal standards of the United Methodist Church.