In The Name of Allaah, The Most Merciful, The Bestower of Mercy
Questioner asked Shaikh Ubaid [may Allaah preserve him]: The questioner says: Assalaamu alaykum warahmatullaahi wabarakaatuhu. We hear a statement from some of the Mashaayihk of Ahlus Sunnah: ‘’This man is from the people of Bidah’’; is it understood that he is a Mubtadi [an innovator] or not?’’
Answer: What I have knowledge of is that this statement has two applications according to Ahlus Sunnah. The first of them and it is what is meant in most cases is that he is a Mubtadi [an innovator]. He knows the truth but he is an obstinate person. He refuses [truth], but not deviation; he knows the Sunnah, but refuses to follow it and [follows] Bidah. He commits Bidah whilst knowing that it is bidah.
The other meaning is that this man is a person upon innovation-meaning: He commits bidah even though he is not an innovator, because what we know regarding the methodology of Ahlus Sunnah Wal-Jamaaa’ah is that they do not declare any specific person an innovator until the proofs are established against him.
[Source: Al-Haddul Faasil Bayna Mu-aamalah Ahl As-Sunnah Wa Ahl Al-Baatil 60. Abridged and slightly paraphrased]