All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
"The righteous predecessors" refers to the companions of the Prophet and the scholars of Islam who followed their way. We follow them because of the following:
1) They had the purest hearts, were the most knowledgeable and the farthest from extremism. Allaah The Almighty praised them in the Quran, promised them Paradise, and indicated that He is pleased with them and that they are true believers. Allaah addresses them Saying (what means): {And the first forerunners [in the faith] among the Muhajireen and the Ansar and those who followed them with good conduct — Allaah is pleased with them and they are pleased with Him, and He has prepared for them gardens beneath which rivers flow, wherein they will abide forever. That is the great attainment.}[Quran 9:100]
2) They are the people in whose language the Quran was revealed, they witnessed the revelation and were undoubtedly the most knowledgeable about what was revealed to the Prophet and were most aware of its purposes.
3) The Prophet testified that they were the best people of this nation. This narration states that the best generation was that of the Prophet then those who followed them, then those who followed them. [Al-Bukhari]
4) The Prophet informed us that there is no salvation (from Hell) if divisions occur among Muslims, except by following his example and guidance and that of his companions . He, sallallaahu ‘alayhi wa sallam, said that the children of Israel divided into 72 sects and that his nation would divide into 73 sects, all of which will be in Hellfire except one, which is the sect that follows his, sallallaahu ‘alayhi wa sallam, guidance and example and that of his companions . [At-Tirmithi]
Allaah Knows best.