The Anglican Church is at risk of "sleepwalk[ing] into fatal compromise", the chairman of the conservative grouping GAFCON said in his Advent pastoral letter this week.
Most Rev Nicholas Okoh, Archbishop, Metropolitan and Primate of All Nigeria and chairman of the GAFCON Primates Council, slammed "the increasing breakdown of church discipline in the Church of England" in reference to clergy who condone gay relationships.
"There are now clergy and bishops who openly take pride in their rejection of biblical preaching and have even launched a website to encourage the violation of the 1998 Lambeth Conference Resolution I.10 on human sexuality," Okoh wrote.
"But more disturbing is the response of the Church of England at its highest level. The Secretary of the Archbishops' Council has written an open letter to Canon [Andy] Lines in which he describes the Lambeth resolution as merely 'an important document in the history of the Anglican Communion'. But this is no ordinary resolution. It has been the standard appealed to again and again in Communion affairs and most recently in the Communiqué from the Sixth Global South Conference in Cairo which describes it as representing the 'clear teaching of Scripture'."
Okoh said the Communion was "standing at the crossroads", and was at a "critical point" in its history.
"Will it return to the ancient paths or sleepwalk into fatal compromise?" he asked.
He said he was "greatly encouraged" by the voice GAFCON had given to orthodox Christianity, but added "great courage" was needed by members to "re-evangelise the increasingly secular West".
GAFCON-UK was last month accused by William Nye, general secretary to the Archbishop's Council, of being "significantly misleading" in a briefing document.
The UK branch of the conservative group had published a list of names of clergy who were in "violation" of Lambeth 1.10. Nye pointed out the resolution was not legally binding but rather expressed the "view of the attitude of the Communion" at the time.
GAFCON-UK then accused the Church of England of being more concerned about "Twitter mobs" than "what is right before God".
It warned the Church's doctrine on marriage was being relegated to "a museum piece".