This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
J. N. D. Kelly's study of the early Christian creeds shows that documents like the Apostles' and Nicene creeds did not arrive complete but developed gradually from shorter, looser baptismal declarations, gaining specific clauses over generations in direct response to real theological disputes the wider church needed to settle.
That documented development matters for a creed entry because it means a creed's final wording often preserves the trace of a specific historical argument, a single clause added to rule out one particular reading a council had rejected, and an entry records that occasion where it is known rather than treating the creed's wording as arbitrary or purely devotional.
A creed entry therefore records not only a creed's final agreed text but, where the documented history allows it, which of its clauses were added at which stage and why, since Kelly's own account shows the creeds' wording and church history are inseparable from each other. That same attentiveness to a clause's origin belongs in every creed entry the atlas holds, whatever tradition produced it.
Kelly's account also shows that a creed's earliest surviving form is very often a local baptismal formula rather than the fixed universal text later generations assumed it always was, and an entry records that local origin honestly where the documented history establishes it.