{If any man willeth to do} (ean tis thel(8869) poiein).
Condition of third class with ean and present active
subjunctive 	hel(8869) not used as a mere auxiliary verb for the
future "will do," but with full force of 	hel(935c), to will, to
wish. See the same use of 	hel(935c) in  5:40  "and yet ye are not
willing to come" (kai ou thelete elthein). {He shall know}
(gn(9373)etai). Future middle indicative of gin(9373)k(935c). Experimental
knowledge from willingness to do God's will. See this same point
by Jesus in  5:46  18:37 . There must be moral harmony between
man's purpose and God's will. "If there be no sympathy there can
be no understanding" (Westcott). Atheists of all types have no
point of contact for approach to the knowledge of Christ. This
fact does not prove the non-existence of God, but simply their
own isolation. They are out of tune with the Infinite. For those
who love God it is also true that obedience to God's will brings
richer knowledge of God. Agnostic and atheistic critics are
disqualified by Jesus as witnesses to his claims. {Of God} (ek
tou theou). Out of God as source. {From myself} (ap' emautou).
Instead of from God.