Kirk officials have joined other denominations including Catholics, Anglicans, Muslims, Sikhs, Quakers and the Free Church urging the government to change the law.
In an open letter, Scotland's First Minister Nicola Sturgeon is urged to make it illegal to buy sex, in a bid to reduce human trafficking.
Currently the law in Scotland criminalises the sale of sex.
Written by the Scottish Churches Anti-Human Trafficking Group it said the law in Scotland should be like Nordic countries where the buyer is criminalised.
"Sex trafficking does not just exist because its victims are vulnerable - it exists because there is a demand for commercial sex that traffickers can exploit and profit from," it said.
It added: "The Nordic model effectively curbs demand and consequently reduces the trafficking for sexual exploitation into the countries that adopt it."
But some campaigners have said a change in the law will make sex workers more vulnerable.
Scotland's Justice Secretary Michael Matheson has offered to meet Kirk representatives to discuss the issue.
A Scottish Government spokeswoman said: "The Scottish Government takes a zero tolerance approach to the exploitation of women and has made significant progress in recent years by strengthening legislation in Scotland.
"Clearly this is a complex issue though which requires careful consideration to ensure that any additional measures which may be required are necessary, practicable and sustainable.
"Any further proposed changes to the law in this area would need to be considered carefully to ensure they are practical in terms of enforcement and whether there is robust evidence to suggest that such proposals would reduce incidents of prostitution or trafficking."