I hear that when you come together as a church, there are divisions among you, and to some extent I believe it. No doubt there have to be differences among you to show which of you have God’s approval.

(1 Corinthians 11:18-19)

The word that is translated ‘differences’ is αἵρεσις hairesis or heresy.

The English language borrowed words from other languages (notably Greek) for concepts our pagan forebears did not have before becoming Christian.  For example, standing in alignment (rihtwis, the right-wise or way) with your king was critical, so we have righteous; but how and why you chose your deity was not: Frige, Thor, Wotan, Tiw, take your pick; mix and match!  

But when the gospel was first preached to the Anglo Saxons in 597AD, Augustine and his fellow emissaries of Pope Gregory, made it very clear that there was one God in three persons, and no syncretic departure was permitted. Thus, to Old English was added hairesis and was anglicised ‘heresy’.

Heresy is now a familiar word, at least, to those of faith; so familiar perhaps, that we lose the full meaning of the word.  Heresy meant (and means) that personal choice of one’s God is proscribed (the literal meaning of hairesis is ‘personally selected’ or ‘self-chosen opinion’).

For the Israelites, heresy was usually described in terms of idolatry, but it amounts to the same thing.  If there is one true God, then to assume we get to define, let alone dismiss or replace, him is clearly nonsensical.  He defines Himself, and is jealous of all praise that is misdirected to some invention by his creatures.

I am the Lord; that is my name;
    my glory I give to no other,
    nor my praise to carved idols.  (Isaiah 42:8)

Christians today do not think themselves as heretics, let alone idolators.  Yet Jesus says a curious, disconcerting and frankly frightening thing:

 ‘Not everyone who says to me, “Lord, Lord”, will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven. On that day many will say to me, “Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?” And then will I declare to them, “I never knew you; depart from me, you workers of lawlessness.”’  (Matthew 7:21-23)

Did not these Christians work in the name of Christ?  Did they not profess him ’Lord’?  How is it, then, they are rejected so abruptly?

The problem comes back to definition.  Saying you worship God is of no moment, if it is a god of singular definition.  To proclaim Jesus as Lord means little if we do not spend anytime heeding the Lord’s commandments and obeying them.  The simple truth is that at heart, humankind is heretical and our natural bent is idolatrous.  

Without the corrective of God’s revealed Word, a remedy taken on a daily basis, we quickly spin off into creating our own God or personal Jesus; such is our instinct for self-invention, that we readily and continually mirror God in our image.  Paul explains this with reference to Adam, who would supplant his Creator and the transformation of a new creation:

As was the man of dust, so also are those who are of the dust, and as is the man of heaven, so also are those who are of heaven.Just as we have borne the image of the man of dust, we shall also bear the image of the man of heaven.  (1 Corinthians 15:48-49)

Note the future tense, we shall bear the image of Jesus, the man of Heaven.  Some might say that Paul speaks to the new creation, the regenerate man, yet, the Apostle warns elsewhere that this new creation is work in progress, or why else does he enjoin all to:

Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry.  (Colossians 3:5)

Without conscious and deliberate effort, we constantly sully the image of Jesus, that imprint of the Spirit, by being naturally idolatrous.  So, Paul would have us embark on this journey of self-denial by each proclaiming that I am, by nature, an idolator and heretic, and left to my own imaginings the God I venerate will be nothing but myself.  

Thus, heresy is an individual choice, not a collective movement.  And this will not be as stark as when we stand in judgment, for there will no one else to plead in mitigation; we all stand alone.  Even if we wish to cite our teachers it will not wash, Paul warns us:

For the time is coming when people will not endure sound teaching, but having itching ears they will accumulate for themselves teachers to suit their own passions, and will turn away from listening to the truth and wander off into myths.  (2 Timothy 4:3-4)

That time is now, and we are those people! And a disunited church is the proof.