Dean Bowyer used her sermon during Wednesday's eucharist mass to reflect on Christmases of her childhood and those faced by the Hunter's residents and emergency services facing devastating climate conditions.

"In the lead up to this Christmas, we have had something new with which to contend; fires that have ripped their way across parched landscapes, and orange sky and a smoke haze ... with no rain at the end. In the midst of this devastation, we have witnessed selfless acts of courage, generosity, and heroism," she said.

Dean Bowyer drew on the Book of Isaiah and verses referring to the sign of Immanuel, a prophesied child in the Gospel of Matthew whose name is used to symbolise 'God is with us'.

"This shared experience has touched deep within us all," Dean Bowyer said. "We cannot remain unmoved in the face of what we see and know.

"God is with us in the midst of all that we hold. What we have seen emerging from the terrible devastation of the fires is a deep desire to care - an outpouring of compassion - an expression of love."

It was a common theme among services on Wednesday.

Bishop Bill Wright, of the Newcastle-Maitland Catholic diocese, dedicated much of his sermon during Wednesday morning's eucharist service at Sacred Heart Cathedral to denouncing what he described as a "cult of celebrity" in contemporary culture, but called on his congregation to remember those battling ongoing bushfires around the state and to take heart from the verses of Isaiah.

Bishop Wright became unsteady during his sermon, at one point giving over his crosier and resting a hand on the altar for support as he continued to address the congregation of around 200.

"You will have to excuse me one moment," he said breaking off mid-sentence partway through his sermon. "I'm just a little unsteady on my feet", before brushing off assistance and attributing the lapse to exhaustion from the earlier midnight service.

"Often it seems that people who have made no particular contribution to the benefit of human kind become famous and much-admired for things that seem relatively trivial at times, but that they happen have the good fortune to be beautiful or funny or powerful, or rich, or to just have the right look," Bishop Wright said.

"What bothers me about that is that it can set up among us an aspiration to be like that. I say that runs counter to the dynamic of Christmas."

As Bishop Wright addressed the nativity scene, he described it as a group of "plain folk" with a deity that represented "everything that is ordinary and plain".

"That is quite a different dynamic to wanting to rise above everyone around us to be better and to be special."