My Christian colleague asked me the following question: why is entrance to the Ka’bah in Makkah forbidden to the Christians and Jews, although (they believe) the Ka’bah belongs to all the messengers?

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Allaah, The Most-High, forbade the disbelievers – the Jews, the Christians and others – from entering the Al-Masjid Al-Haraam because they are impure.

Allaah The Almighty Says (what means): {O you who believe (in Allaah's Oneness and in His Messenger (Muhammad)! Verily, the Mushrikun (polytheists, pagans, idolaters, disbelievers in the Oneness of Allaah, and in the Message of Muhammad) are Najasun (impure). So let them not come near Al-Masjid Al-Haraam (at Makkah) after this year…}[Quran, 9:28] This text indicates that it is forbidden for disbelievers to enter the Holy Mosque, because they are impure. What is meant here by ‘impure’ is not physical impurity but spiritual impurity, because their hearts do not believe in Allaah The Almighty and they worship other than Allaah The Almighty.

Their saying that Al-Masjid Al-Haraam is a house for all the prophets and messengers is unquestionable, but that does not mean that the disbelievers who pretend to be on the religion of Musa (Moses) and ‘Eesa (Jesus), may Allaah exalt their mention, can enter it. In reality, these people are disbelievers who are contradicting the true religion of those prophets and messengers.

Allaah Knows best.