In his Articles of Faith, written first in a response to a newspaperman about Mormon beliefs, Joseph Smith lists faith in the Lord Jesus Christ as the first principle of the gospel. It's easy to see why. Faith seems to be a motivating force guiding believers to action.
Mormons tend to differentiate between belief and faith, with the difference that faith moves one to act, where belief might not. And faith might affect outcomes, as well. The verse from James that Joseph read before retiring to the woods to pray reminds, "Let him pray in faith, nothing wavering" (James 1:6).
So if faith motivates to one to act, it may also signal an expectation for an outcome, as well (faith to be healed, faith to receive answer to prayer, faith to choose well).
I draw another parallel for faith from the business world. I go to work each day in good faith, assuming my employer will pay me at the end of the month. A house seller acts in good faith by taking his house off the market when he has an acceptable offer from a buyer. I pay an online merchant with my credit card in good faith, assuming he will ship the items I have purchased. In each of these examples, I have an assumption of the outcome.
Jesus in the New Testament speaks of faith as a power that leads to miraculous outcomes. If we demonstrate enough faith we may enjoy the blessing we seek.
So here is a small conundrum for me. On the one hand, I believe God to be all powerful and completely capable of doing whatever He determines to do, within whatever constraints He (or the laws under which he operates) has placed upon himself. On the other hand, my earthly father's example taught me that I ought to be humble and not make too many demands on God. So when I act "in faith, nothing wavering," I suppose I need to be cautious about whether my faith is in the potential of God to answer my prayer (absolutely) or in the outcome (maybe not so much).
If I have faith in Jesus Christ, to return to that first principle, then I might act confidently according to His teachings and commandments. Even if I do not have a perfect knowledge, as the Book of Mormon prophet Alma calls it, I can operate with faith, as if I knew.
In my own life, this is how my testimony has developed over the years. I have, from time to time, without knowing the end from the beginning, taken a step into the unknown, with faith (or at least hope) that a promised blessing would materialize. Honestly, my performance in this matter has been somewhat variable. Sometimes I have felt as if I've demanded a blessing, and other times, I've hoped for a blessing that has seemed not to have come. But despite my unevenness, over time, the pattern seems to be that when I act in good faith, the Lord finds a way to demonstrate to me that He has kept his side of the bargain.