Schools Minister David Laws is being asked to re-think the decision to exclude Religious Education from the English Baccalaureate.
The RE:ACT campaign, spearheaded by Premier Christian Radio, warns in a letter that religious illiteracy could have "international implications as inter-faith suspicion and intolerance continue to manifest themselves across the world, with devastating results".
The RE:ACT coalition includes faith organisations from across the UK and was launched in 2011 to campaign for the inclusion of RE as a humanities option within the EBacc.
Speaking on behalf of the campaign, Premier chief executive Peter Kerridge said: "The state, in whatever country, has a duty to ensure that their children are given the opportunity to learn about and understand the world's dominant religions if future generations are to have a hope of co-existing, side by side, in harmony.
"State negligence in this area of their education will have far-reaching consequences."
He said the exclusion of RE had "adversely affected" the quality and delivery of the subject in schools. The letter draws attention to a report from an All Party Parliamentary Group on Religious Education published last month which found that more than half of RE teachers in secondary schools have no qualifications or expertise in the subject.
The report identifies falling numbers of applications in RE teacher training courses and a failure among RE teachers to meet teaching standards as a result of inadequate training.
A petition by the RE:ACT campaign attracted 150,000 signatories in support of RE and was presented to 10 Downing Street in September 2011.
Mr Kerridge asked the Schools Minister to explain how the Government plans to remedy the poor quality of RE teaching.