The post wrote, "In nature, procreation is the single relentless rule. That is the norm. Our sexual bodies were designed for reproduction," a quote by American academic and social critic, Camille Paglia.
"No one is born gay. The idea is ridiculous," it concludes.
Williams' employer Scripture Union labelled the post as "inappropriate" and affirmed the group's support to people regardless of their sexual orientation.
"Chaplaincy is about supporting people whatever their issues are, and it's just unfortunate that someone's acted outside of that," Scripture Union chaplaincy development manager, Peter Swift, said.
Troy Williams, a youth worker with Kingborough Council in Tasmania and a chaplain at Hobart College, will join other youth workers and chaplains at the LGBTI forum, hosted by gay rights campaigner and author, Daniel Witthaus.
He has since apologised on ABC News for the "offence caused" and has agreed to work with his employers to ensure there is no repeat of the incident.
"I've made a mistake and learnt from it," Williams said. "I was very careless in posting that image for discussion."