Dallin H. Oaks
"Just as we will be accountable for our evil desires, we will also be rewarded for our righteous ones. Our Father in Heaven will receive a truly righteous desire as a substitute for actions that are genuinely impossible. My father-in-law was fond of expressing his version of this principle. When someone wanted to do something for him but was prevented by circumstances, he would say: ’Thank you. I will take the good will for the deed.’
"This is the principle that blessed Abraham for his willingness to sacrifice his son Isaac. The Lord stopped him at the last instant (see Genesis 22:11-12), but his willingness to follow the Lord‘s command ’was accounted unto him for righteousness’ (D&C 132:36).
“This principle means that when we have done all that we can, our desires will carry us the rest of the way. It also means that if our desires are right, we can be forgiven for the unintended errors or mistakes we will inevitably make as we try to carry those desires into effect. What a comfort for our feelings of inadequacy!” (Pure in Heart, p. 59)
Brigham Young
"No matter what the outward appearance is--if I can know of a truth that the hearts of the people are fully set to do the will of their Father in heaven, though they may falter and do a great many things through the weaknesses of human nature, yet, they will be saved… .
“If their motives are pure--no matter whether their outward appearance is particularly precise, their acts will be discerned by the Spirit of the Lord, and will be appreciated for what they were intended. If people act from pure motives, though their outward movements may not always be so pleasant as our traditions would prefer, yet God will make those acts result in the best good to the people. (Journal of Discourses 5:256.)” (Dallin H. Oaks, Pure in Heart, pp. 59-60)