The letter to The Daily Telegraph states that the proposed orders, which are designed to "tackle extremism in all its forms" are so wide ranging that they have the potential to include a host of preaching practices.
It read: "Many are anxious that the Government's current response risks going seriously off-track.
"The stated goal of ministers - to tackle 'extremism in all its forms' - casts the net so wide that almost anyone could fall into it.
"Many people will fall foul of EDOs and, as the former head of MI5 has said, 'harmless evangelicals' could be among them."
The letter emphasises that Theresa May's disruption orders "look set to rely on a test of extremism that threatens the very democracy they are meant to protect."
Signatories include Revd Tony Jones Senior Minister, Christchurch, Durham, Revd Dr Mike Ovey, Principal, Oak Hill College, Nola Leach, Chief Executive, Christian Action Research and Education, Colin Hart Director, The Christian Institute
and Andrea Minichiello Williams, CEO, Christian Concern.
The letter concludes: "Today Christians can be labelled "extremists" by those who disagree with Christianity.
"For some such people, EDOs will be a gift. For the Church, they will be a disaster."