Ibn al-Qayyim, said:
No Muslims are in disagreement [about the fact] that intentionally leaving obligatory prayers is from the greatest of sins and from the most major of major sins and that its sin is greater than the sin of murder or [unlawfully] taking [others’] wealth; than the sin of fornication and adultery, theft, or drinking alcohol–and that [the one who intentionally leaves a prayer] faces the punishment of Allāh and His wrath, His debasement in this life and the Hereafter.
Al-Albānī. Ḥukm Tārik Al-Ṣalah. Dār Al-Jalalain, 1412 H, p. 5.
N.B.: Title mine (Trans.)