You must not allow yourselves to become discouraged. Missionary work brings joy, optimism, and happiness. Don't give Satan an opportunity to discourage you. Here again, work is the answer. The Lord has given us a key by which we can overcome discouragement: "Come unto me, all ye that labor and are heavy laden, and I will give you rest. Take my yoke upon you, and learn of me; for I am meek and lowly in heart; and ye shall find rest unto your souls. For my yoke is easy and my burden is light."