How the Disbelievers Manage to Encroach upon Muslim Lands
Imām Ibn Taimiyyah, may Allāh have mercy on him, said:
Among the things that lead to the disbelievers encroaching upon the lands of Muslims is the appearance of ilḥād,¹ hypocrisy, and bidaʿ.²
¹deviation from the truth and what’s right into disbelief, misguidance, or sinfulness (tr.)
²acts of worship invented by people, not legislated by Allāh (tr.)
Majmūʿ Al-Fatāwá, vol. 13, p. 180.