بسم الله الرحمن الرحيم
Shaykh Salih states: Abandoning the prayer in totality is disbelief -we and our brothers seek refuge with Allah from such- and there is ample evidence to support this in the Quran, Sunnah, and consensus (of the Authentic Scholars). The Exalted says,
فإن تابوا و أقاموا الصلاة و آتوا الزكاة فإخوانكم في الدين
“So if they repent, establish the prayer, and pay the zakah (only) then they are your brothers.” [At-Taubah: 11]
and He says
…ما سلككم في سقر قالوا لم نك من المصلين
“What has caused you to enter Hell? They will say we were not of those who prayed.” [Al-Muddathir: 42-43]
Likewise from the sunnah is that which is narrated on the authority of Jabir ibn Abdullah where the Prophet said, “Indeed between a man (standing like a barrier) and between polytheism and disbelief is the abandonment of prayer.” Likewise that which is narrated by some of the compilers of (varying) sunan that which is upon the authority of Buraydah ibn Husayb wherein the Prophet said, “The covenant that distinguishes us from them is the prayer. Whoever abandons it has disbelieved.” Collected by Ahmad and others and it is an authentic hadith.
As for consensus of the scholars, Abdullah ibn Shaqiq said, “The companions of Muhammad did not consider the abandonment of anything from their actions to be disbelief except the prayer.” Collected by Tirmidhi and others with a sound chain.
Translated by Najeeb Al Anjelesi
Source: المنظار في بيان كثير من الأخطاء الشائعة