Its most difficult to imagine that some one or some group of poeple plooting to hurt / kill innocents who have come there to perform the most noble rite humans can do to pray. With this environment of fear people would slowly start doing there religious rites from home, and less poeple would come to the commen religious place. We are heading for situation where the religious places would be needing more security. The security could be like private or govenment provided. Only poeple who are menbers of that Mosque , church or Temple would be allowed in after verification of there identity. We are definitly headed to this situation. With such times approching it would be difficult to pray.