The main entry notes that Eliade contrasted cyclical, mythic time with the linear, irreversible history of the Abrahamic traditions, but does not explain why early Christian thinkers treated this contrast as an urgent theological stake worth arguing about directly.
Stoic cosmology, mentioned in the main entry, held to ekpyrosis, a periodic cosmic conflagration after which the universe is reconstituted in every detail exactly as before, including, in the more rigorous statements, the same individuals living the same lives in endless repetition, a position early Christian apologists, Origen and Augustine among them, identified as directly opposed to the Christian claim that Christ's incarnation, death and resurrection were unique, unrepeatable events decisively changing history's direction. Augustine, in The City of God, argued explicitly against the cyclical cosmologies of pagan philosophy, holding that an endlessly repeating cycle was incompatible with Christian hope, since it would mean Christ must be crucified again in every cycle, a conclusion he treated as blasphemy against the sufficiency of the one crucifixion, insisting instead on a linear history moving from a unique creation through a unique redemption to a unique consummation.
This is the theological stake behind Eliade's later, academic framing of Abrahamic linear time as a historical innovation: for Augustine the issue was a doctrinal necessity, since Christian soteriology requires the incarnation and resurrection be unrepeatable, once-for-all events rather than one iteration of an endlessly recurring pattern, which is why rejecting cyclical cosmology became a live, doctrinally load-bearing commitment rather than a descriptive difference later comparative religionists would notice.