Lord Needed a Prophet, pg. 10; “Joseph watched in wide-eyed wonderment as the personage moved toward him without touching the floor…Joseph was spellbound. He listened to the angel tell how, when the right time came, he—a poor farm boy—would be able to translate the ancient writing on the plates of gold. He would have the help of the Lord and two small stones called the Urim and Thummim…Moroni told Joseph many other marvelous things, but finally the light began to diminish, and Moroni disappeared. He returned to Joseph’s bedside two more times during the night…” – Susan Madsen
Galatians 1:6-9; “I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel: 7 Which is not another; but there be some that trouble you, and would pervert the gospel of Christ. 8 But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. 9 As we said before, so say I now again, If any man preach any other gospel unto you than that ye have received, let him be accursed.”
This passage from the Bible is what further convinces me God knew in advance about Mormonism.