The latest church census in Scotland showed that the number of regular churchgoing Christians in the country has fallen to 390,000, representing 7.2 percent of Scotland's population, down from 854,000 (17 percent of population) in 1984.
The study also showed that 42 percent of the churchgoers were aged over 65, and that the number of congregations dropped from 4,100 in 1984 to 3,700 in 2016, the report said.
Lead researcher Dr. Peter Brierley said the figures indicated that Scotland faces a crisis in Christianity.
"We are living in the 21st century and one of the features of the 21st century is that people's allegiance to particular faiths is no longer as strong as it used to be," he said.
Brierley said the decline in church attendance was mainly due to the deaths of elderly churchgoers.
"Part of the problem is the proportion of people in the church who are elderly is much greater than in the population of Scotland as a whole," he said.
"So, you have a great number of churchgoers dying. The rate of replacement is not as many. That's the basic reason for decline."
He said the problem is not because Christians are turning to other faiths. "In general terms that is not the case," he said. "There are also quite a lot of invisible Christians who used to go to church, still believe in God, but they have moved house, perhaps to a rural area, and simply haven't found a church to go to."
Commenting on the census results, the Reverend Dr. David Pickering, Moderator of the United Reformed Church Synod of Scotland, said it did not make for "terribly happy reading."
"It's a crisis and an opportunity. Both present themselves," he said, adding that it "presents a new opportunity for the church to portray the love of God and the good news of Jesus in a new way for a new generation. That's an opportunity and a challenge for us."
Pickering said church leaders have to acknowledge that "most congregations have more older people than younger, and most young people simply do not see the relevance of God, of Jesus, of the church, to their lives."
The Bishop of Paisley, John Kennan, also expressed concern over the fall in church attendance.
"The real crisis that's going on is not that people aren't coming to us; it's that we've stopped going to them," he said.
In January this year, an Episcopal Cathedral in Glasgow, Scotland, stirred controversy after it allowed the reading of a verse from the Quran that states that Jesus Christ is not God's Son during a church service.
St. Mary's Episcopal Cathedral provost, the Very Rev. Kelvin Holdsworth, at the time defended the service, saying that it was aimed at fostering relationships between Christians and Muslims.
Some church leaders criticized the Quran reading inside a church, calling it "ill-advised."