Anti-Islam protesters stormed Gosford Anglican Church in response to the church's pro-immigration stance.
It's reported a group of about 10 people dressed in Islamic clothing entered the church chanting mock Muslim prayers.
The protesters belong to the organisation Party for Freedom. In a Facebook post, the group said patriots had stormed the "house of apostasy".
It continued: "This morning Party for Freedom members and supporters stormed Rod Bower's Anglican Church, Gosford in protest against him and his congregation for supporting Islam and multiculturalism."
The group posted several videos on Facebook of similar stunts throughout the day.
Father Rod Bower, who leads the church said his congregation was in shock.
Speaking to ABC, he said: "[The protest] was simply because we support the Muslim community, we try and build bridges.
"To come into sacred space, to violate that space as Christians were celebrating the ultimate act of love ... to bring hate into that space is a deep violation. It just galvanises our conviction."