The word enthusiasm comes into English from the Greek word entheos which means “inspired or possessed by a god.” Literally entheos is derived from the prefix en- meaning in and the word theos meaning God. In the 1600s the word as applied to the Puritans took on a negative connotation of excessive zeal. Today the word has a positive meaning of fervor and zeal.
The word enthusiasm never appears in the scriptures. However, the synonym zeal is used by some of the scriptural writers. Mormon tells us of the people of Ammon–the converted Lamanites–who were “distinguished for their zeal towards God, and also towards men; for they were perfectly honest and upright in all things; and they were firm in the faith of Christ, even unto the end” (Alma 27:27). When I read about the people of Ammon, I am struck by how happy they were. Enthusiasm and joy always go together. Living the gospel wasn’t a chore for them. They delighted in it. They were possessed by God and knew He would care for them. All they had to do was enthusiastically and joyfully serve Him.
When the Lord wants to encourage us to be enthusiastic He tells us to give Him all our heart, might, mind, and strength (see D&C 59:5). I think that’s pretty much all of me! It may seem strange that by giving our love, our material goods, our thoughts, and our abilities to the Lord we will be happy. But I know it works because I’ve experienced it. The days of my life when I’ve been able to give all of myself have been the most joyful. When I am enthusiastic about the gospel, when I give myself to God, His love fills me and I am happy.
“I withheld not my heart from any joy; for my heart rejoiced in all my labour: and this was my portion of all my labour” (Eccl 2:10).