I hadn't remembered seeing the Faust talk before, so thanks for bringing it to my attention.
In reading your emphasized snippet, it did make me think of the shift that seems to have occurred in the ~160 years between 1850 and today. In 1851, Orson Pratt wrote this:
The Book of Mormon claims to be a divinely inspired record... If false, it is one of the most cunning, wicked, bold, deep-laid impositions ever palmed upon the world, calculated to deceive and ruin millions... if true, no one can possibly be saved and reject it: if false, no one can possibly be saved and receive it...
If, after a rigid examination, it be found an imposition, it should be extensively published to the world as such; the evidences and arguments on which the imposture was detected, should be clearly and logically stated....
But on the other hand, if investigation should prove the Book of Mormon true... the American and English nations... should utterly reject both the Popish and Protestant ministry, together with all the churches which have been built up by them or that have sprung from them, as being entirely destitute of authority...
(Orson Pratt's Works, Divine Authenticity of the Book of Mormon, Liverpool, 1851, pp. 1-2)
I have emphasized in this passage what I believe to be telltale markers of Pratt's faith in the foundations and doctrines of Mormonism. He is absolutely confident in his faith. So confident that he feels safe in admonishing people to investigate, to examine, to study.
Even as late as the 1950's, over one hundred years later, Joseph Fielding Smith seems to echo this sentiment of confidence that the Church of Jesus Christ of Latter-Day Saints will withstand any scrutiny a skeptic might bring to bear:
Mormonism must stand or fall on the story of Joseph Smith. He was either a Prophet of God, divinely called, properly appointed and commissioned or he was one of the biggest frauds this world has ever seen. There is no middle ground. If Joseph was a deceiver, who willfully attempted to mislead people, then he should be exposed, his claims should be refuted, and his doctrines shown to be false.
(Joseph Fielding Smith, Doctrines of Salvation, vol. 1 pp 188-189.)...
In this quote, Smith does not explicitly invite the the skeptic to examine the truth claims of Mormonism, but that invitation is clearly implied.
Faust, in his 1986 address, seems to be recommending the opposite approach as his predecessors.
It is important for us to nurture such a simple, untroubled faith. I urge complete acceptance of the absolutes of our own faith. At the same time, I urge you not to be unduly concerned about the intricacies, the complexities, and any seeming contradictions that seem to trouble many of us. Sometimes we spend time satisfying our intellectual egos and trying to find all the answers before we accept any.
This quote quite clearly asks each of us not to investigate, not to consider, not to question.
Assuming you agree with me that these quotes truly represent a shift in emphasis over time, to what would you attribute this shift?
What prevailing conditions or causative events, in your estimation, might be the root cause of this shift?