15 Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves.
16 Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles?
17 Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit.
18 A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit.
19 Every tree that bringeth not forth good fruit is hewn down, and cast into the fire.
20 Wherefore by their fruits ye shall know them.
For me, part of the beauty of that passage is its universal application, because of the many situations we find those who claim to be or act as our prophets, yet turn out to be deceivers.
In the many situational definitions we can apply to the term "false prophet", in each case His observations and advice about recognizing deceivers remain solid and sound.
Not just those who claim to prophecize on God's behalf, but any of those who predict or make promises in our lives.
The older I get and more I've lived through, the more I see such universal truths in the Bible. Years ago, I would not have said this, but now I see that everything we need is in that book. It's like nothing else.