The simple believeth every word: but the prudent man looketh well to his going. Proverbs 14:15
When he speaketh fair, believe him not: for there are seven abominations in his heart. Proverbs 26:25
Prove all things; hold fast that which is good. 1 Thessalonians 5:21
Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world.
1 John 4:1