But now Jehovah's Witnesses are embracing modern technology to bring Scots Gaelic speakers to the sect.
Jehovah's Witnesses, currently attending a 1000s-strong rally in Glasgow, are reaching out to Gaelic speakers by translating Bible tracts from English and evangelical web pages into the ancient Celtic language. The Scottish contingent of the Christian denomination said they are "moving with the times" to attract more followers.
About 9000 Jehovah's Witnesses have gathered at The SSE Hydro in Glasgow - the first conference to be held in the music venue. The three-day convention, which ends today, is linking up with similar events across the UK and Ireland to provide simultaneous talks to a total audience of 175,000 Witnesses.
Jehovah's Witness and Gaelic-speaker, Eilidh Bond, originally from the Isle of Skye and now living in Grangemouth, said: "Parts of our website are available in so many languages, including Scots Gaelic. There's a lot of people at the conference who have just become Witnesses and have never been to a convention before. They'll be informed that Gaelic is available."
Bond, 30, said there was a push to attract more people to the religion and using Gaelic and the internet was part of that process. Gaelic is spoken by about 58,000 people in Scotland.
"A lot of people were surprised, pleasantly surprised, about the effort we made," said Bond. As well as literature and Bible passages, Witnesses have started translating other pages on their website into Gaelic.
Bond said: "We think it's so important to translate as much of it into Gaelic as possible. So far it's been really appreciative.
"Not only do we have Gaelic literature available, but we've recently started translating the actual pages into Gaelic. So Gaelic speakers and learners can read the guides."
She added: "It's a good opportunity, especially up in the islands, where we're able to inform people about the website and the Gaelic tracts."
Bond said sections of future conventions could be held entirely in Gaelic.
Earlier this month households in Belfast began receiving religious tracts in Irish. The move is part of a month-long global campaign. There are plans to print the tract, called Where Can We Find Answers To Life's Big Questions?, in Welsh, as well as Gaelic.
The organisation, which has almost eight million members worldwide, currently prints its literature in 681 languages.
Witness Don Benham, 46, who lives near Airdrie, North Lanarkshire, said the religion wanted to reach out to people in the "language of their hearts".
He said: "We feel that having it in the language that people were brought up in enables them to understand it better."
Despite the move to provide information online, the organisation still concentrates on old-fashioned evangelism and knocking on doors.
Benham said: "We're trying to keep up with the way people get information nowadays. We're moving with the times. The internet is the big thing so we've focused on upgrading the website and making it known to people that that's the way they can get information.
"It's just another way. We still do the door-to-door work and the traditional methods we've used for the last 100 years or so."