Non-muslims not allowed in Mecca/Madina
Why does Quran ban non-Muslims to enter Mecca/Madina? "Oh you who believe! Truly the idolaters are unclean; so let them not, after this year, approach the Sacred Mosque...." (9:28)or God is just for Muslims and non-believers can't even enter in the house of God?
The ban was for the generation of polytheists (and only polytheists) who had rejected the messenger of God despite receiving God's message from him directly in the most convincing manner. The injunction has nothing to do with the rest of times nor it had to do with the People of the Book of those times either. It was a punishment for the polytheists of that time for the double fault they had committed: for rejecting the messenger of God despite receiving his message directly and for insisting on committing polytheism despite getting clear evidence against it from God's Book. The Qur'an has clarified that the direct addressees of all messengers of God (Rasul) were punished. It is an inviolable divine law.