“Is it bad to bring my mobile phone to church?” New Era, Nov. 2012, 45
Merely having a phone in your possession at church isn’t bad in and of itself, but there aren’t many reasons to use it there (looking up scriptures in class, perhaps, and … well, that’s about it). If for whatever reason you can’t leave it at home or in the car, turn it off and put it someplace where it will not tempt or distract you at church. This is the time set aside for your worship. Both you and those you communicate with should understand and respect this fact.
In addition, using your phone in church can distract others. Elder Dallin H. Oaks of the Quorum of the Twelve Apostles has said, “During sacrament meeting—and especially during the sacrament service—we should concentrate on worship and refrain from all other activities, especially from behavior that could interfere with the worship of others. … Young people, it is not a time for whispered conversations on cell phones or for texting persons at other locations” (“Sacrament Meeting and the Sacrament,” Ensign, Nov. 2008, 18–19).