Inspectors will criticise the varying quality of England's 150 RE syllabuses in a report later this month.
The Office for Standards in Education's conclusions will follow a TES survey which this week reveals widespread support for new national guidelines for RE.
Currently RE syllabuses are drafted by groups in each local authority.
Almost two-thirds of these Standing Advisory Councils for Religious Education (Sacres) responding to the survey said their syllabuses were likely to be redrawn in the light of new guidelines.
The guidelines, or framework, unveiled by Education Secretary Charles Clarke last month, are intended to address concerns over widely differing standards and claims that RE is being increasingly marginalised in schools.
The Professional Council for Religious Education has already said that up to 20 per cent of the locally-agreed syllabuses are ill-informed.
More than a third of the country's 150 Sacres responded to the TES survey.
They said the framework was needed to iron out huge "inconsistencies" nationwide.
Of 52 Sacre representatives who responded, 92 per cent said they approved of the framework. One member of a Sacre in the North-east said: "The content and quality of RE varies widely between authorities and this is unacceptable." An adviser from Yorkshire said: "The lack of a national framework devalues RE."
Ofsted is expected to criticise patchy national standards in RE.
While 62 per cent of Sacres said their syllabuses would need revising, a quarter said the framework would not influence RE lessons in the near future because syllabuses had only just been finalised.
The new guidelines recommend that schools teach children about secular views from the age of five and that minority religions, including Jainism and Baha'i, should be taught alongside Christianity and other principal faiths.
Last week The TES revealed that hundreds of schools were preparing to defy the recommendations by refusing to teach non-religious views in RE lessons.
Guy Hordern, chairman of the Birmingham Sacre, one of England's biggest, criticised the teaching of secular beliefs, saying it had no place in RE lessons.
The city's Agreed Syllabus Conference will be held next year, when it will be decided whether or not to incorporate part of the framework into Birmingham's RE lessons.
However, 77 per cent of those who responded to the survey said they backed plans to teach views such as humanism. As many as 73 per cent said existing syllabuses already took non-religious views into account.
The survey revealed most Sacres would resist moves to force schools to adhere to the new guidelines with 57 per cent saying local power should be retained over RE.
However, 31 per cent said they would support coercion. One said: "There must be parity between RE and the national curriculum subjects to secure its status in practice as well as law."
The latter view is supported by senior figures in the Church of England, including Dr Kenneth Stevenson, Bishop of Portsmouth, and chair of the church's board of education. The C of E has already outlined plans to write to all its church school governors urging them to adopt the framework.
Additional reporting:Patrick Hayes and Emily Whitchurch