An apostle of The Church of Jesus Christ of Latter-day Saints spoke Sunday to a segment of society that, taken in the aggregate in the United States, is among the most likely not to be affiliated with a religion. Elder D. Todd Christofferson’s talk to the Church’s global cadre of young adults ages 18 to 30 addressed, fittingly, several major concerns that may cause some of them to shy away from a life committed to faith or religious community.