Athanasius believes that human beings are inherently unstable, just because they are creatures. For Athanasius, the stability of salvation rests, Anatolios argues, in the inner-Trinitarian life of giving and receiving. Explaining the “anointing” of Psalm 45 as an anointing of the Son by the Spirit, Athanasius argues as follows (the wording is from Anatolios):

“Salvation is definitively secured when there is a perfect communication between the divine giving of the Spirit and the human receiving of the Spirit, as happens in Christ. In him, the giving is perfect because he is God, who is by nature the giver of the Spirit; the receiving is perfect because he is God in human form; and the perfect union of giving and receiving is established in that the same one is perfect giver and perfect receiver . . . . for Athanasius [Psalm 45] signifies the christological dialectic whereby the immutability of the Word underwrites humanity’s perfect reception of the Spirit through its participation in Christ’s human reception of the Spirit.”

We are secure, stable in fellowship, because we are corporated to the Son who assumed humanity and perfectly received the Spirit. His reception is the surety of ours.