Ideas about the Kingdom of the Heavens around us and the unity of believers in Christ within it
“Heresy” cannot be determined by calling anything that goes in a different direction that specific leaders a heresy, because leaders are sometimes wrong. Peter is an example, though he repented when rebuked for his divisiveness in Antioch.
Divisions in the church have been started not only by leaders who taught license to attract followers, but also by leaders who taught extreme asceticism– that God is only pleased by those who keep the strict rules they prescribe.
1 Timothy 6 also warns about people who create arguments in order to exploit them for financial gain and to build their own authority. This warning is presented in the context of teaching about respect for human authority and authority in the Church.
Factions, “hereseis,” as used in 1 Corinthians 11:19, clearly does not refer to divisions caused by false teachers. Instead, in that context, it refers to divisions caused by neglect and humiliation of poor believers and by the formation of personality cults.