[you will] have joy in [your] works for a season, and by and by the end cometh

 At a meeting I attended one Sunday, a young woman asked something like the following: “My boyfriend and I recently broke up, and he chose to leave the Church. He tells me he has never been happier. How can this be?”
The Savior answered this question when He said to the Nephites, “But if [your life is] not built upon my gospel, and is built upon the works of men, or upon the works of the devil, verily I say unto you [you will] have joy in [your] works for a season, and by and by the end cometh.” There simply is no enduring joy outside the gospel of Jesus Christ.

Taking upon Ourselves the Name of Jesus Christ

October 2018

General Conference

Robert C. Gay

https://www.churchofjesuschrist.org/study/general-conference/2018/10/taking-upon-ourselves-the-name-of-jesus-christ?lang=eng&verse=#p