How do we know if a preacher is true?

First John 4:1 advises believers to test the spirits to determine whether they are from God, highlighting the need for discernment in spiritual teachings. This requires a careful examination of what is being preached in light of Scripture, as many false prophets have gone out into the world. It is essential that the preaching aligns with the person and work of Christ as revealed in the Bible, ensuring that the message is not influenced by human opinion or error, but is faithful to God's Word.