[Source: Fatâwâ Noorun ‘alâ-Darab of Shaykh ‘Abdul-‘Azîz Ibn ‘Abdullâh Ibn Bâz, volume 1, pages 12-13] :
Many groups and sects claim that they are the Saved Sect, and the affair has become unclear to many people, so what should we do, especially that there are many groups who have ascribed themselves to Islam, like the Soofiyyah and Salafiyyah, and their likes from the many various groups, So how do we distinguish (the saved sect from the rest of the deviant groups)? May Allâh bless you.
The Prophet (May the praise and security be upon him) said: “the Jews split into 71 sects,” meaning, all of them are in the Fire except one, the followers of Musâ (alayhis salâm); “and the Christians split into 72 sects,” meaning they are all in the Fire except one, those who followed ‘Îsâ (alayhis salâm); “and this nation will split…”, meaning the Ummah (nation) of Muhammad (May the praise and security of Allâh be upon him), “…into 73 sects, all of them will be in the Fire except one.” He was asked: O’ Messenger of Allâh, “Who are the Saved Sect?” He said: “Al-Jamâ’ah.” And in another narration: “That which I and my Companions are upon.”
This is the Saved Sect, those who gather upon the truth which the Messenger brought, remain steadfast upon it, and proceed upon the methodology of the Messenger (May the praise and security of Allâh be upon him) and the methodology of his Companions. They are the People of the Sunnah and Al-Jamâ’ah (‘the group’), the people of the noble Hadeeth, the Salafiyyoon who follow the Righteous Predecessors, and proceed upon their methodology in accordance with the Qur’ân and Sunnah, and every sect that opposes them is threatened with the Fire.
So it is upon you, O questioner, that you look into every sect that claims to be from the Saved Sect, and look at their actions, then if their actions are in accordance with the Shari’ah then they are from the Saved Sect, or otherwise they are not, and it is intended that the scales by which to weigh is the Great Qur’ân and the purified Sunnah in reality for every sect, so whoever’s actions and speech is in accordance with the Book of Allâh and the Sunnah of the Messenger (May the praise and security of Allâh be upon him), then this enters them into the Saved Sect. And whoever opposes them, like the Jahmiyyah, the Mu’tazilah, the Râfidah, the Murji’ah, and other than them, and predominantly the Sufis, who innovate into the religion that which Allâh has not permitted, all of them enter into the sects which the Messenger threatened with the Fire, until they repent from that which opposes the Shari’ah.
Every sect contains within it an element of opposition to the pure Sunnah, so it is upon them to repent from it, and return back to the correct way, back to the truth which Our Prophet Muhammad (May the praise and security of Allâh be upon him) brought. With this, you will be saved from the threat of punishment, but if you remain upon the innovations which have been introduced into the religion, and not remain steadfast upon the way of the Messenger (May the praise and security of Allâh be upon him), then it enters them into the threatened sects, and not all of them are disbelievers, rather they are threatened with the Fire. It may be that from amongst them there is someone who is a disbeliever due to carrying out an act of kufr (disbelief), and it may be that there is one from amongst them who is not a disbeliever but is threatened with the Fire, due to his act of innovation in the religion, and his legislating in the religion that which Allâh has not permitted (Far removed is He from all imperfections, the Most High).
 Reported by Tirmidhî in Kitâb Al-Emân, Hadîth 2641 & by Ibn Mâjah in Kitâb Al-Fitan, Hadîth 3992