Terry,
Logical development of the formula in the progression laid out in the Bible:
(1) Anyone can believe without faith in God, (e.g. The demons believe, but are faithless)
(2) Anyone can do works without faith in God, (e.g. Matthew 7:21-23)
(3) No one who has an active and living (vital) faith in God will fail to believe, his faith will inform his beliefs.
(4) No one who has an active and living (vital) faith in God will fail to demonstrate works, his faith will motivate works.
(5) Certain characteristics will always be present in somone who has an vital faith in God.
(6) These characteristics may be imitated falsely, but their absence will always show eventually
Therefore, just as you cannot possibly know for sure whether someone respects you, you cannot possibly know whether someone has faith or simply puts on a show of faith. Fortunately, in the Scriptures, it doesn't make one jot of difference whether you can determine the faith of someone else.
The JWs have the formula messed up in that they believe:
(1) Whether or not you have faith you should do works, because
(2) Faith arises from works
Whereas, the Scriptures consistently state the opposite, to wit, "by faith" certain works were done. (Hebrews 11) I hope this helps.
Respectfully,
OldSoul