Answer
Wa `alaykum As-Salamu waRahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
It is permissible for non-Muslims to enter mosques and Muslims should seize such opportunities to introduce Islam to them in the best way.
Responding to your question, Dr. Muhammad Salama, PhD in Islamic Studies in English and an Assistant Professor at the Faculty of Islamic Science, Al-Madinah International University, states,
Authentic hadiths tell us that the Messenger of Allah (peace be upon him) received non-Muslim individuals and delegations in his mosque. He even tied a non-Muslim captive, named Thumamah ibn Uthal, to one of the pillars of his mosque, to let him watch Muslims performing their prayers; and finally the man accepted Islam.
Therefore, it is permissible for non-Muslims to enter mosques and Muslims should seize such opportunities to introduce Islam to them in the best way. But it is noteworthy in this context that those non-Muslims have to show respect to the mosque and to Muslims in terms of their clothes and conduct inside the mosque.
It is only prohibited for them to enter the Sacred Mosque in Mecca as mentioned in Surat al-Tawbah, verse 28.
Allah Almighty knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.