John 7:17 in the King James Version
If any man will do his will, he shall know of the doctrine, whether it be of God, or whether I speak of myself.
Context
16 Jesus therefore answered them, “My teaching is not mine, but his who sent me.
17 If anyone desires to do his will, he will know about the teaching, whether it is from God or if I am speaking from myself.
18 He who speaks from himself seeks his own glory, but he who seeks the glory of him who sent him is true, and no unrighteousness is in him.