Thats just the catholic churches lying definition of it. Arianism denies the trinity. Not that Jesus is divine. From Arius' own words... "We acknowledge One God, alone unbegotten, alone everlasting, alone without beginning, alone true, alone having immortality, alone wise, alone good, alone sovereign, judge, governor, and provider of all, unalterable and unchangeable, just and good, God of the Law and the Prophets and the New Testament; who begat an only-begotten Son **before time and the ages**, through whom he made both the ages" Arians deny Jesus is a co-eternal member of a trinity of Gods that has always existed, because the bible says no such thing.