The Athanasian Creed, following the teaching of Scripture, calls Christ “perfect God and perfect man.” It beautifully affirms that in the incarnation there was a “taking on” of a human nature rather than the divine nature somehow mutating into a human one.
Athanasius was one of the early church’s most significant theologians.
He was born at the end of the third century in the city of Alexandria, which was a cultural hot spot in the Roman Empire.
Not much is known about Athanasius’ upbringing or education, but he started working for the bishop of Alexandria (who was called Alexander, confusingly) and eventually became bishop of Alexandria himself.
When Athanasius was about twenty years old, a dangerous heresy arose. And it was a heresy he would famously oppose for the rest of his life—at great cost to himself, given how popular the teaching became. It wasn’t until the very end of his life that the false teaching was finally put to death. In fact, Athanasius is often depicted in paintings as standing over a defeated heretic.
The heretic in question was an Alexandrian deacon called Arius, forty years the senior of Athanasius, whose teaching became known as Arianism. Arianism taught that although Christ was without doubt an exalted creature, He was nevertheless only a creature. According to Arius, the Son of God was made by God the Father, and therefore was less than God. That is, the Son of God did not exist as a coeternal member of the Godhead from all eternity.
The popularity of this teaching compelled early church leaders to assemble in Nicaea (in modern-day Turkey) in 325 AD. There they formulated the Nicene Creed, which clearly set out a biblical answer to Arianism: Jesus Christ, the second person of the Trinity, has the same substance or essence as the Father (the key word they used was homoousios, a Greek word meaning “of one substance”). The Son of God is (quote) “begotten, not made, of one being with the Father.” In other words, the Bible teaches that all three persons of the Trinity—Father, Son and Spirit—are equal in being and eternality.