Around 800 men and women packed the Mount Pleasant Baptist Community College to hear from the two leaders.
During discussion about euthanasia, Mr McGowan reaffirmed his view that individuals should be free to make their own choices.
Mr Barnett opposes euthanasia.
"I do not support euthanasia, I do not support having a legal structure for finishing a life," he said.
The pair was also quizzed about abortion with Mr McGowan saying there is a place for the practice.
Both he and the Premier agreed current regulations about abortion should continue.
However, the leaders had different opinions about gay marriage.
Mr McGowan supports it.
"If I was a member of federal parliament, I'd vote for it," he said.
Mr Barnett received wide applause for his stance.
"Marriage is between a man and a woman and that is one of the basic fabrics and structures of our society," he said.
Both leaders agreed that more had to be done to tackle mental health and suicide.