Shiekh Saleh Fawzan answered a question asked by one Muslim on How to deal with a work colleague who doesn't pray. The Shiekh simply said that the one who doesn't pray is an infidel and must be killed.
according to this Fatwa u have to waste ur time and interrupt ur work to do something as useless as praying so that ur colleagues would be happy and pleased with u, otherwise they will kill u cold…