What does the Bible teach about false prophets?

In Matthew 7:15-20, Jesus cautions His followers to beware of false prophets who appear as harmless but are actually 'ravening wolves' in sheep's clothing. Their true nature is revealed through the fruits of their teachings and actions. The New Testament frequently warns against those who mix works with grace, promoting a false doctrine that undermines the gospel's core message of salvation by grace alone. Christians are called to be discerning, testing spirits and adhering to sound doctrine to avoid the deception that often accompanies false teachings.