Shaikhul Islaam Ibn Taymiyyah (rahimahullah) said:

”And under the guises of those ones who pronounce Takfeer based on falsehood are a people who do not know the creed of Ahlus Sunnah Wal-Jamaa’ah as it is obligated, or they know some of it and are ignorant of some of it.  They conceal that which they know of it and do not clarify it for the people. They neither forbid innovations nor censure Ahlul Bidah and punish them; rather they may even censure a statement in the Sunnah and a fundamental of the religion completely, and they would not differentiate between what Ahlus Sunnah Wal Jamaa’ah say and what Ahlul Bidah Wal Furqah (i.e. the people of innovation and splitting) say, or they would affirm all their differing ways. (i.e. declare all of them correct even though the path of Ahlus Sunnah is the only truth)”

[Majmoo Al-Fataawaa 12/467]