According to extant history the development of some of its main tenets ("The Doctrine of the Blessed Trinity" and "consubstantialism") clearly do not have their roots in the scriptures (and are refuted by Hebrews 1:3) so do they consider their use of Gnostic thought to be part of their "Sacred Tradition"?:
...The term ὁμοούσιος had been used before its adoption by the First Council of Nicaea. The Gnostics were the first to use the word ὁμοούσιος, while before the Gnostics there is no trace at all of its existence. The early church theologians were probably made aware of this concept, and thus of the doctrine of emanation, taught by the Gnostics. In Gnostic texts the word ὁμοούσιος is used with the following meanings:
Identity of substance between generator and generated. Identity of substance between things generated of the same substance. Identity of substance between the partners of a syzygy.
For example, Basilides, the first known Gnostic thinker to use ὁμοούσιος in the first half of the 2nd century AD, speaks of a threefold sonship consubstantial with the god who is not. The Valentinian Gnostic Ptolemy claims in his letter to Flora that it is the nature of the good God to beget and bring forth only beings similar to, and consubstantial with, himself. The term ὁμοούσιος was already in current use by the 2nd-century Gnostics, and through their works it became known to the orthodox heresiologists, though this Gnostic use of the term had no reference to the specific relationship between Father and Son, as is the case in the Nicene Creed...
In other words, was the Creed of "Athanasius" (though attribution is to a man of the 4th century AD doubtful as it rests on one man, Erasmus, from the middle ages based on style) developed from pagan ideas by the "Holy Ghost" or received by divine inspiration through a single inspired Catholic deacon?