Rex Murphy seems to think that religion should over-ride democracy.
Firstly, the idea that Christians MPs need to impose their faith on others by banning stuff is ludicrous. Christian MPs who are strongly against abortions, shouldn't have abortions. Should Muslim and Mormon Liberal MPs be allowed to leverage their Liberal party status to try to bring back prohibition? Or ban sex before marriage? Or outlaw condoms? No.
Religious radicals are free to form their own party. That's what the Conservatives did.