The Rt Rev Dr Iain Greenshields pointed to the current pressure on resources and said the Kirk was “very concerned” about the issue.
His intervention comes as Liberal Democrat MSP Liam McArthur is expected to introduce a members' Bill on assisted dying later this year.
Mr McArthur’s legislation would allow mentally competent adults who are terminally ill to end their lives. Two doctors would need to confirm a person was terminally ill and mentally competent, and there is a suggested reflection period of 14 days.
It is the third attempt to legalise assisted dying in Scotland.
Writing in today’s Scotsman, Dr Greenshields said the Kirk has repeatedly opposed any change in the current law, adding: “Our opposition is based on our Christian faith and includes concerns around the principle of assisted dying, around the application of the law in practice, the perception value of human lives, and also the effect this change is likely to have on the provision of care, especially palliative care.”
Dr Greenshields said other jurisdictions had seen safeguards relaxed.
He added: “We are concerned that, should assisted dying be legalised, the way our society views older people and those with disabilities will, over time, become more utilitarian. The lives of those on the margins of society will inevitably come to be seen as less valuable or even burdensome. Is this really the kind of society we aspire to?”
The moderator said evidence from other jurisdictions also suggested “allowing assisted dying has a negative effect on the importance placed on palliative care”.
He continued: “Given the pressure on healthcare resources, we are also very concerned that assisted dying could be seen as providing an opportunity for cost-saving.
"An analysis from Canada, referred to in the consultation document for the legislation shortly to be considered by the Scottish Parliament, states that a 2017 cost analysis of assisted dying concluded that ‘medical assistance in dying could reduce annual health care spending across Canada by between $34.7 million [£20.8m] and $138.8m [£83.3m]’.”
The concerns have been raised as Scotland’s NHS battles record accident-and-emergency waiting times and ‘bed blocking’ problems during what First Minister Nicola Sturgeon has described as the “most challenging winter ever”.
Dr Iain Kennedy, chairman of the BMA in Scotland, last month said the nation needed to “face up to the hard truths that have been put off for far too long, and have a proper, grown-up, de-politicised national conversation about the future of our NHS in Scotland”.
Mr McArthur said: “Let me be very clear that my only motivation in bringing forward proposals for a new assisted dying law is to give dying people who are suffering unbearably the peace of mind that they do not need to suffer against their will.
"At the moment dying people in Scotland are not able to choose the death that’s right for them.
“In bringing forward legislative proposals, MSPs are required to produce robust financial information that detail the costs of setting up a new system, but also provide evidence of potential savings. However, this is not the reason why I am bringing forward this legislation. This Bill is solely about ensuring dignity and choice for those at the end.
“The evidence shows that where the right to an assisted death exists, palliative care spending goes up, not down – this is because there is a greater focus on end-of-life care and treatment.
"My Bill proposals include that two doctors would outline alternative treatment and care options to someone seeking an assisted death. I want to see strong investment in palliative care in Scotland, alongside a change in the law on assisted dying, and will be vigorously making this case as the proposed Bill goes through Parliament.”
A Scottish Government spokesman said it was “committed to ensuring that everyone has dignity and respect at the end of their life, and will carefully consider the substance of any Bill that is introduced”.
The spokesman added: “We also remain committed to supporting the delivery of the very highest standards of care, right up to the end of life, and to developing and delivering a new strategy on palliative and end-of-life care.”