In the formative years of the LDS Church, any revelation received by church members was only considered valid if it was approved by Joseph Smith, because any revelation that contradicted Joseph”‘s just couldn”‘t be true. It pains me to think how the Spirit of God was stifled in the hearts of those who thought they had found truth in Mormonism, and were taught to reject all feelings of doubt and disbelief because those feelings must be from the devil. 

For more information, see The Mormon Mirage 3rd Edition:  A Former Member Looks at the Mormon Church Today (Zondervan, 2009). Also available as an audiobook and as an expanded-text E-book for Nook, Kindle and other reading devices.