Criticism On Quran
God is not just merciful, He is Just too. If His mercy prevails upon the evil doers, it is cruelty in itself. So, to be Just is the outcome of being merciful. and Justice entails punishment too for evil doers. God is even merciful to sinners when they repent, but he never extend His mercy to who commit sin or infidelity knowingly and then do not repent. The killing of the Polytheist of Arabia was a special order of Allah which is not likely to extend to all non-Muslims. That special order falls under the Law of Itmam ul Hujjah. According to the law, the direct addresses of a Rasul eventually put to death after the truth is communicated to them conclusively.