Al-jawab billahi at-taufeeq (the answer with Allah's guidance)
In general, It is permissible to bring or permit a non-Muslim into the Mosque.
It is stated in al-Fatawa al-Hindiyya that,
�There is nothing wrong with non-Muslims (Dhimmis) to enter the Haram of Makkah (al-Masjid al-Haram), and all other mosques. This is the sound opinion in the Madhhab, as mentioned in al-Muhit of Sarakhsi.� (Al-Fatawa al-Hindiyya, 5.246)
It is also mentioned by Imam Kasani in his Badai' al-Sana i' and others is that delegations of non-Muslims would meet with the Prophet (Sallallahu Alaihi Wasallam) in Masjid-e-Nabawiy.
The opportunity should be to make Da'wah to non-Muslims.
