Open Matthew 7:15-20.
Matthew 7:15-20 (my translation)
15 Watch out for those who claim to speak for God but don’t. They present themselves as sheep following God, but they’re viscous wolves inside. 16 You’ll recognize them by what they produce. People can’t get grapes from thornbushes, or figs from thistles. 17 Every good tree makes good fruit; but a worthless tree makes degenerate fruit. 18 A good tree cannot make degenerate fruit, and a worthless tree cannot make good fruit.
19 Every tree that doesn’t make good fruit is cut down for firewood. 20 You can certainly recognize them by their fruit.
What does this have to do with Jesus’ kingdom message? Because we treat religion and politics as unrelated categories, we miss what Jesus meant about false prophets. Jesus’ kingdom message is a threat to those who want power. Conversely, those who want power want to conscript God to affirm their leadership. False prophets are those who affirm false powers — rulers other than Jesus.