Major Sins (End)

Ibn Mas'ud (may Allah be pleased with him) related that the Prophet (pbuh) said, "Hold your tongue whenever you hear the mentioning of my Companions, stars and destiny.”2

Scholars argued that, holding one's tongue is a sign of complete submission to Allah. It is obligatory for a Muslim to love Allah and his Messenger. Of the Prophet's love is to love all what
He was sent with, those who take after him, those who apply his tradition and guidance, household, companions, wives, progeny, servants, and to love whoever loves them and hate whoever hates them. Abu Ayyub As-Sakhtiyyani (may Allah be pleased with him) said, whoever loves Abu Bakr raises the minaret of the religion higher, whoever loves 'Umar clarifies the way, whoever loves 'Uthman, is enlightened by Allah's light, whoever loves Ali adheres to the clearest principle and whoever says, the Prophet's companions are good and right is free from hypocrisy.
As for the virtues of the Prophetic companions, they are countless. The best of the companions are the ten whom the Prophet promised to enter paradise. The best four of them are Abu Bakr, 'Umar, 'Uthman and' Ali (may Allah be pleased with them all). Whoever doubts them, is a hypocrite.

In the hadith narrated by AI-'Irbad Ibn Sariyyah, the Prophet said, "You must follow my deeds (Sunna) and that of the rightly guided caliphs. Hold it and stick fast to it. Avoid novelties (in religious matters), for every novelty is an innovation and every innovation is an error and
every error is in hell.” 3
The Rightly-Guided Caliphs are: Abu Bakr, 'Umar, 'Uthman and , Ali. The former was mentioned in the Qur'an several times. "Let not those among you who are endued with grace and amplitude of means resolve by oath against helping their kinsmen, those in want, and those who have left their homes in Allah's cause" (An-Nur: 22)

{ Being the second of the two, they two were in the care.} (At- Tawbah: 40)
{And he who brings the truth and who confirms (and supports) it.} (Az-Zummar: 33)

1 Ash-Shawkani attributed it to Aqily in Durr As-Sahabah and said it is a weak hadith.
2 As-Suyuti attributed it to At- Tabarani in Jami' Al-Adhkar.
3 Reported by Abu Dawud.