why has sexuality become so important to conservative Christians?

The newly formed “Diocese of the Southern Cross” has broken away from the Anglican Church of Australia to form a denomination committed to a highly conservative position on sexuality and marriage equality.

Global Anglican Futures Conference (GAFCON), the association supporting the breakaway denomination, claim Anglican bishops “were unable to uphold the Bible’s ancient teaching on marriage and sexual ethics”, making their defection necessary.

One question Australians, the majority of whom support marriage equality, may ask is – why is sexuality such a significant issue for the Christians who have left to form this group, and many conservative Christians generally?

According to GAFCON, the answer is “orthodoxy”. In the sense used here, orthodoxy refers to “right teaching” (this is broader than the word’s more specific meaning in Eastern Orthodox Christianity). Permitting anything other than heterosexual relations or marriage, GAFCON argues, is a departure from Christianity’s long-held orthodox stance.

However, this understanding of orthodoxy is not “ancient teaching”, but new.

The claim that sexuality has always been central to Christianity is shaky

Historically, Christian orthodoxy had nothing to do with sexuality.

The first time there was a need for Christians to define orthodoxy was in the late third century. Around this time, a renegade priest named Arius began teaching that Jesus Christ was an important human being, but not the divine Son of God.

Beginning with the Council of Nicaea in 325 CE, seven Ecumenical Councils of the church were convened in order to establish the orthodox “doctrines and dogmata” – theological statements and principles – about the nature of God and Jesus.

The formal statements of belief were orthodox because they concerned what might be called Christianity’s “logic of salvation” – how humanity was saved from sin and death by Jesus.

“Heresy”, or false teaching, was perceived as a threat to the faith’s existence.

Read more: Anglican disunity on same-sex marriage threatens to tear the church apart

Not only is the claim that sexuality is central to Christian orthodoxy dubious, but it’s not certain same-sex sexuality has always been condemned by the church. Bible scholars such as William Loader and Heather R. White call into question the interpretation of Biblical passages that conservative Christians claim exclude same-sex sexuality.

Historians like John Boswell, Judith C. Brown, and Mark D. Jordan have shown that while same-sex sexuality was at times prohibited, at other times it was tolerated and even celebrated over the course of Christian history.

So the argument that sexuality has always been central to Christian orthodoxy is shaky. Yet, it seems that for some conservative Christians, this view of sexuality has become more important than doctrines that really are central to orthodoxy, traditionally understood.

Read more: A thousand years ago, the Catholic Church paid little attention to homosexuality

So why is sexuality so important to conservative Christians now?

This leaves us with our initial question unanswered – why is sexuality so important for this group of Christians now?

One answer is to be found in the work of the 20th century French academic Michel Foucault.

Foucault was fascinated by how certain ways of understanding and speaking about the world actually shape what we can see and say – making some things very visible and important, while other things become invisible and impossible.

Foucault called this “discourse”, which for him had a broader meaning than our everyday usage. He argued discourse was more than words or discussion on a topic. Discourse includes that, but also the practices, language, techniques and overall conditions that produce the acceptable “truth” in relation to something.

In The History of Sexuality, Foucault argued sexuality was the discourse of sex, or the set of conditions that create the acceptable “truth” concerning sex. He observed two such discourses, both emerging in the mid-19th century.

The first was concerned with classifying sexual practices in order to declare some healthy and normal, and others wrong or requiring “treatment”.

The second was a “reverse discourse”, opposed to the criminalisation of homosexuality and promoting sexual freedom.

Conservative Christians tend to align with the first discourse, firmly holding that same-sex sexuality is opposed to God’s “truth” of sex. In fact, being the ones who have the authority to say what is and is not the “truth” of sexuality has become a marker of who is “really” Christian. As Church of England priest and educator Mark Vasey-Saunders puts it, “an issue that had never featured in any evangelical basis of faith came to represent the definitive mark of authentic Christian identity”.

The conflict that has led to the Diocese of the Southern Cross breaking away from the Australian Anglican church isn’t based on ancient teachings, as the new group claim. The ancient meaning of “orthodoxy” had nothing to do with sexuality, but concerned matters related to the nature of God and Christian salvation.

The position of the new denomination is the result of a modern discursive conflict over the “truth” of sex. The fact that sexuality has become central in a way it never has been before helps explain why this group decided it was important enough to leave their former church. It couldn’t be more important, as in this new “orthodoxy” the cost of giving ground is ceasing to be truly Christian at all.