The church has been heavily involved in the campaign against marriage equality across the Tasman.
Earlier this week, Brisbane Archbishop Mark Coleridge compared same-sex love to "the love of friends" and said same-sex "can't be the kind of love that we call marriage".
Last month, Archbishop of Melbourne Denis Hart called upon Australian Catholics to vote "no" on the postal survey, a message also sent out by the Archbishop of Perth, Timothy Costelloe.
Wall says the church has no business trying to portray itself as a "moral crusader".
"I wish you'd talk about it and say to them, 'If you want to be a moral crusader, why don't you eliminate child sexual abuse? And be a leader in that?'" she said in the podcast. "Not against human rights, and especially in a process where young Australians are being so adversely affected.
"I find it absolutely appalling that they've come out and been so vigorous in their opposition."
She talked about the time New Zealanders successfully campaigned for marriage equality and became the first nation in the Asia Pacific region to give same-sex couples the right to legally marry.
"I believe that's where we were able to break down the generational divide. Grandparents started looking at their grandchildren and saying, 'I want for my grandchild what I want for all people. I want them to find that person and get married and have a good home and a good life and children.'"