How do you tell the difference between the noise in your head and the Voice of God? You have a moment of profound peace in prayer, a sudden clarity, but by Thursday morning you are wondering if you just manufactured the entire experience to make yourself feel better.

In the Sixth Mansion of The Interior Castle, St. Teresa of Ávila provides a clinical survival manual for spiritual discernment. Writing under the terrifying scrutiny of the Spanish Inquisition, she knew that mistaking your own ego—or the enemy—for God wasn't just confusing; it was highly dangerous. One Good Book explores her practical tests for interior "locutions"—words or impressions that seem to come from outside your own thoughts—and why a manufactured message requires exhausting mental labor, while God's voice arrives like a stone suddenly thrown into a still pool.

The ultimate litmus test is the "Rule of Effect." Just as the Apostle James insisted that real faith produces visible works, Teresa insists that true divine speech always produces the reality it names. When you try to convince yourself not to be afraid, the fear remains. But when the King speaks, His word instantly creates the peace He commands.

This episode is for you if you have ever felt a nudge in prayer and then spent two days paralyzed by the fear that you were just talking to yourself.

You don't need to be a brilliant analyst of your own soul. You only need to inspect the fruit at justonegoodbook.com.