How do we know that Christ's teachings have authority?

The authority of Christ's teachings is substantiated by the reactions of those who hear Him. In Mark 1:22, the people are astonished at His doctrine because He teaches as one having authority, unlike the scribes who teach from tradition. This astonishment indicates a profound impact that His words have on the minds and hearts of the hearers. Additionally, Christ's teachings align with and fulfill Old Testament prophecies concerning the Messiah, asserting His position as the long-awaited Savior. His teachings, filled with grace and truth, reveal the very nature of God's redemptive plan and carry the authority to lead sinners to repentance and salvation.