Why Are Non-Muslims Not Allowed In Makkah
According to the Quran, the idol worshipers shall not be permitted to approach the Sacred Masjid in Mecca.
[9:28] O you who believe, the idol worshipers are polluted; they shall not be permitted to approach the Sacred Masjid after this year. If you fear loss of income, GOD will shower you with His provisions, in accordance with His will. GOD is Omniscient, Most Wise.
We can derive the reason for the above restriction from the following verses:
[9:107] There are those who abuse the masjid by practicing idol worship, dividing the believers, and providing comfort to those who oppose GOD and His messenger. They solemnly swear: “Our intentions are honorable!” GOD bears witness that they are liars.
[9:108] You shall never pray in such a masjid. A masjid that is established on the basis of righteousness from the first day is more worthy of your praying therein. In it, there are people who love to be purified. GOD loves those who purify themselves.
[9:109] Is one who establishes his building on the basis of reverencing GOD and to gain His approval better or one who establishes his building on the brink of a crumbling cliff, that falls down with him into the fire of Hell? GOD does not guide transgressing people.
[9:110] Such a building that they have established remains a source of doubt in their hearts until their hearts are stilled. GOD is Omniscient, Most Wise.
The Quran teaches us tolerance. It does not impose any other restriction on idol worshipers, for example, visiting Mecca, Medina, Arafat, or any other places.
[9:6] If one of the idol worshipers sought safe passage with you, you shall grant him safe passage, so that he can hear the word of GOD, then send him back to his place of security. That is because they are people who do not know.
[9:19] Have you considered the watering of the pilgrims and caring for the Sacred Masjid a substitute for believing in GOD and the Last Day, and striving in the cause of GOD? They are not equal in the sight of GOD. GOD does not guide the wicked people.