Adam Clarke on John 7:17

If any man wilt do his will, etc. - I will give you a sure rule by which ye may judge of my doctrine: If you really wish to do the will of God, begin the practice of it; and take my doctrine, and apply it to all that you know God requires of man; and if you find one of my precepts contrary to the nature, perfections, and glory of God, or to the present or eternal welfare of men, then ye shall be at liberty to assert that my doctrine is human and erroneous, and God has not sent me. But if, on the contrary, ye find that the sum and substance of my preaching is, That men shall love God with all their heart, soul, mind, and strength, and their neighbor as themselves; and that this doctrine must bring glory to God in the highest, while it produces peace and good will among men; then acknowledge that God has visited you, and receive me as the Messiah promised to your fathers.