Here you can find texts on the issues related the the distinction between the Sunnah and the bida’ (innovation) and between the people of the Sunnah and the people of bida’. The Salaf have laid down firm principles and explained the rules of these issues very clearly in order to remove the confusion of the confused, and the doubt of the arrogant.
Usul As-Sunnah – by Imam Ahmad ibn Hanbal
The last of this Ummah will not be correct except through that which the first of it was correct by
The footnote of ‘Adil Alu Hamdan regarding Abu Hanifah
Whoever opposes only one principle from the principles of the Sunnah, then he is an innovator
Some issues regarding the people of innovation
The manhaj of the Salaf in using the words of the Sahābah (radiAllāhu ’anhum) as an argument and the saying of Mujāhid regarding Muhammad (sallAllāhu ‘alayhi wa sallam) sitting upon the Throne