Statistically, attending a weekly worship service is a remarkably safe thing to do. Global annual attendance totals many billions; the number of people killed in attacks on individual houses of worship in any given year is generally less than a few hundred.
Yet high-profile deadly attacks in recent years — with targets including synagogues in England and Pennsylvania, two mosques in Christchurch, New Zealand, and a Catholic church in the United States hosting a Mass for school children — have intensified anxiety and outright fear among clergy and worshippers worldwide.
