The highest most sacred dogmatic formulation of Christianity is the so-called “Credo” or “Symbol of Faith” (full text here; more info here). Literally every letter down to the smallest ‘i‘ of this text is, from the Christian point of view, the most sacred and perfect dogmatic formulation, backed by the full authority of the two Ecumenical Councils which proclaimed it and all the subsequent Councils which upheld it. In simple terms – the Symbol of Faith is absolutely non-negotiable, non-re-definable, non-re-interpretable, you cannot take anything away from it, and you cannot add anything to it. You can either accept it as is, in toto, or reject it.