The story of the Trinity

This is something I have to learn by heart.
At the beginning of the fourth century, there were many models by which Christian theologians attempted to grasp the nature of the interrelations of Father, Son, and Spirit, and to determine to which of the three Persons—and in what manner—it was correct to apply the name “God.” Scripture made it impossible, of course, to deny Christ at least some ascription of divinity, and equally difficult to reject the divinity of the Spirit. But it was by no means clear to all that the three divine Persons should be understood as co-equally, co-eternally, or “co-essentially” one and the same God. Hence, the most appealing, intellectually sophisticated, and plausible fourth-century alternative to what would become Nicene orthodoxy was some variant of “subordinationism.” This was the school of thought (especially well established in the great city of Alexandria) that saw the Son and Spirit as derivative and lesser emanations of the Godhead of the Father—“economically” reduced versions of God mediating between the transcendence of the Father, who dwelt in light inaccessible, and the darkness of the material world.


Quoted from David B. Hart at First Things.