If you are in a church in which many people seem to keep their Smartphones pointed at someone's back, neck, or head for the entire service, you are probably dealing with demonized congregants. They are being told by their demons and spirit guides that they must radiate the person in front of them in order to prevent their light from shining too brightly. Satan likes darkness, his demons enjoy darkness, and therefore, any form of light becomes an annoyance to them.
If your church has more than one or two demonized congregants, you are in danger of being seriously injured. Either you should ask your priest or pastor to deal with the congregants, or you should leave the church and worship at home. In a year or two, you may be able to rejoin the church, or find a different church in which to worship.
The Lord God Almighty El Shaddai