I've been attempting to learn The Apostles' Creed. I can remember most of it in English, and am now working on it in Greek, as found in Michael Bird's What Christians ought to Believe.

While I was in the throes of this endeavour, I came across a discussion on Twitter initiated by Emily McGowin, Assistant Professor of Theology at Wheaton College. She asked people for a short definition of heresy. 

I appreciated these definitions of heresy and/or heretics:

Luke Stamps: a deliberate departure from the consensus of the church on a theological matter of primary importance (grounded in the clear teaching of Scripture, summarised in the ecumenical creeds and councils).

Justin Holcomb says Heresy is a specific and direct denial of any of the central beliefs of the Christian church about the deity and identity of the triune God and about the person and work of Christ.

Christy Thornton said that A heretic is a person who wilfully holds a well-developed belief that fundamentally corrupts the gospel and who has rejected the correction of the church.

Hazel Motes couldn't help being the first to make this comment, later repeated by others who didn't notice that the joke had already been made: A heretic is anyone who deviates by even one degree from the particular ways that I choose to articulate every aspect of Christian theology

Several people pointed out that you can't become a heretic unintentionally. Most people thought adherence to the historic creeds is important and refutes the charge that a person is a heretic. A couple of people talked about the charge of heresy being used as an oppressive weapon. John Manzo said Doctrine is bullshit. Christ's presence is how we interact with one another.

As I chewed these over, I realised that some folk elevate the creeds over the Scriptures themselves, maybe saying "You don't need to affirm an inerrant Bible or believe the lot, but you do need to assent to the creeds." But I think that using creeds and councils wisely should lead us to embrace embrace God's written Word in its fullness, not to stripping it of its wild, uncomfortable content.