Cardinal Keith O'Brien, in an interview with the BBC, said members of other religions must recognize that Scotland's "core faith" is Christian, The Scotsman reported.
Muslim and Hindu leaders objected to his remarks.
"Mr. O'Brien should be addressing his comments to Christians," said Inayat Bunglawala of the Muslim Council of Britain. "I think Muslims are surprised that many Christians don't take their faith so seriously."
Mike Parker, general secretary of the Evangelical Alliance Scotland, said Christians should be more public about their faith.
"Talking too much about Jesus is not our biggest problem in Scotland; a lot of Christians keep it quiet," Parker said.
Michael Matheson, a member of the Scottish Parliament and culture spokesman for the Scottish National Party, suggested O'Brien was doing his job.
"A major part of Cardinal O'Brien's role is to spread Christianity," Matheson said.