Are non Muslims allowed to enter a mosque or other places of Islamic worship?

Qur’an 9:28 describes polytheists using the word “najas” (impurity). For many Muslims, this implies non-Muslims are unclean and thus should not be permitted to enter a Muslim place of worship. What really does this verse mean, and are non-Muslims really considered filthy in Islam? Does Islam really advocate the disrespect and prevention of non-Muslims from entering mosques? This video explores the meaning of “najas” in the context of Qur’an 9:28, and the practice of the Prophet Muhammad with respect to non-Muslims entering mosques.