Allow All Men the Same Privilege

The Prophet Joseph Smith

"We claim the privilege of worshiping Almighty God according to the dictates of our own conscience, and allow all men the same privilege, let them worship how, where, or what they may."

- The Prophet Joseph Smith, Articles of Faith 1:11

If you are looking for an explanation of how this article of faith ought to play out in real life, you could definitely do worse than Professor Daniel Peterson's Mormonism, Islam, and the Question of Other Religions.  In fact, as far as statements on religious tolerance go, there are probably not many better.