Alma 22:12-13

12 And it came to pass that when Aaron saw that the king would believe his words, he began from the creation of Adam, reading the scriptures unto the king—how God created man after his own image, and that God gave him commandments, and that because of transgression, man had fallen.

13 And Aaron did expound unto him the scriptures from the creation of Adam, laying the fall of man before him, and their carnal state and also the plan of redemption, which was prepared from the foundation of the world, through Christ, for all whosoever would believe on his name.

Nothing has more powerful effect than the word of God.

(Or in other words, the Word of God.)