Orson Pratt
"There is a great difference between faith and knowledge. I am told that there is such a country as China on the eastern borders of Asia; but I never have been there; I never have seen that country; I cannot say, most positively, that such a country exists, only on the testimony of others I am informed that such is the case. I believe that testimony, but it is not a perfect knowledge to my own mind, obtained by my own experience. And so in regard to ten thousand other facts or events. We are in many, indeed in almost all, instances required to believe without a knowledge." (Journal of Discourses, vol. 16, p. 209)
Boyd K. Packer
"(quoting Alma 32:21) In keeping faith I hope you are able to know that there are some things that must be taken on faith; and that, in our insatiable quest for knowledge, always preparatory to and preliminary to gaining spiritual knowledge there is the exercise of faith. As the prophet Moroni said, 'Dispute not because ye see not, for ye receive no witness until after the trial of your faith' (Ether 12:6)." (Let Not Your Heart Be Troubled, p. 147-8)
Howard W. Hunter
"There are many things which are invisible to our senses and not subject to positive proof. The scientific approach to proof is by experimentation in the laboratory. The result of this scientific method has a greater influence upon our thinking than we realize, because it produces positive proof resulting in knowledge. We cannot overlook the great good this approach by science has upon the lives of persons, but how about those things which lie outside of the realm of positive, tangible proof? This question brings us to the higher law. It is through the assurance that comes from faith.
"The classic example of faith is ascribed to the Apostle Paul in his Epistle to the Hebrews: 'Now faith is the substance of things hoped for, the evidence of things not seen.' (Heb. 11:1.)
"This statement does not presuppose a perfect knowledge, but describes faith as that which gives to one an assurance or a confidence in things which are yet in the future. These things may be in existence, but it is through faith they are realized. Faith gives a feeling of confidence in that which is not visible or susceptible of positive proof." (Conference Report, Oct. 1962, p. 23)
Orson F. Whitney
"Perfect knowledge swallows up faith, and removes the opportunity for its exercise: while through the exercise of faith, made manifest by good works, we obtain the spiritual development for which we entered upon this our second estate." (Conference Report, Apr. 1911, p. 48)
Neal A. Maxwell
"It is to be understood, however, that hope is not the same as perfect knowledge. (See Alma 32:21.) Once we have actually seen, said Paul, it 'is not hope.' (Romans 8:24.) Thus hope, like faith, is not quite knowledge. Yet, being at the border of knowledge, we can see through 'glass darkly' enough of the future to affect how we live today." (Notwithstanding My Weakness, p. 42)
Spencer W. Kimball
"The exercising of faith is a willingness to accept without total regular proof and to move forward and perform works. 'Faith without works is dead' (James 2:26), and a dead faith will not lead one to move forward to adjust a life or to serve valiantly. A real faith pushes one forward to constructive and beneficial acts as though he knew in absoluteness. The Prophet Alma gave the near perfect address on faith in the thirty-second chapter of Alma. He gives us: 'Faith is not to have a perfect knowledge of things; therefore if ye have faith ye hope for things which are not seen, which are true.' (Alma 32:21.)
"Faith is the planting of seeds, the taking of steps. Faith is the child, and when nourished and fed, grows into maturity and becomes adult in deep assurance and perfect knowledge." (The Teachings of Spencer W. Kimball, p. 72)