A campaign has been launched by parliamentarians and faith groups to attract a new generation of Religious Education teachers.
It follows a year-on-year decline in the number of people applying to teach the subject.
The latest data from UCAS (the Universities and Colleges Admissions Service) shows a 22% drop in teacher recruitment across all subjects.
However, the fall in recruitment for RE teachers is even steeper, at 33%.
Despite the decline in RE teacher numbers, the subject is growing in popularity in school, with entries to the full GCSE course rising by 30% over the last decade.
Culham St Gabriel's Trust, which is supporting the campaign, blamed "government inaction" for the teacher shortage.
The Beyond the Ordinary campaign has been launched in a bid to reverse the downturn.
Kathryn Wright, Chief Executive Officer of the Culham St Gabriel's Trust, said: "Religious education is an important curriculum subject enabling children and young people to navigate our complex multi religious, multi secular society.
"Everyone has a worldview, and it's important we prepare young people to become free thinking, critical participants in public discourse, who can make informed judgements about matters of religion or belief and reflect meaningfully on the big questions in life."
Lord Karan Bilimoria said: "The latest teacher recruitment figures are deeply worrying. Parents are concerned, schools are concerned and so too the young people are missing out.
"As a Champion for RE, I've heard numerous times from students that this is one of the few times in the classroom where they get to say what they think about the world around them.
"At present we face doing a disservice to a generation of young people ill-equipped to deal with the complexities of belief in Britain and the world beyond.
"This campaign is about getting the best humanities graduates into the classroom to help them deliver a modern RE curriculum reflective of belief in our society."
