Our created purpose, to become divinized (not deified as a casual reading of the single line of +Athanasius above might lead one to believe), lost through the sin of Adam, became possible again, in a triumph over the very Death that our sinfulness brought into the world, only through God's grace and the sacrifice, the physical death, of Christ. We are told to follow Him, to become like Him, even in death and thus enter into a true communion with the Triune God. The Fathers almost all speak to us of this and the very points you raise. "A person is perfect in this life when as a pledge of what is to come he receives the grace to assimilate himself to the various stages of Christ's life. In the life to come perfection is made manifest through the power of deification." +Gregory of Sinai "The dispensation of our God and Saviour concerning man is a recall from the fall, and a return from the alienation caused by disobedience to close communion with God. This is the reason for the sojourn of Christ in the flesh, the pattern of life described in the Gospels, the sufferings, the cross, the tomb, the resurrection; so that the man who is being saved through imitation of Christ receives the old adoption. For perfection of life the imitation of Christ is necessary, not only in the example of gentleness, lowliness, and long suffering set us in His life, but also of His actual death. So Paul, the imitator of Christ, says, `being made conformable unto His death; if by any means I might attain unto the resurrection of the dead.' How then are we made in the likeness of His death? In that we were buried with Him by baptism." +John Chrysostomos "The Son of God has become Son of Man in order to make us...sons of God, raising our race by grace to what He is Himself by nature, granting us birth from above through the grace of the Holy Spirit and leading us straightway to the kingdom of heaven, or rather, granting us this kingdom within us (Luke 17:21), in order that we should not merely be fed by the hope of entering it, but entering into full possession thereof should cry: our 'life is hid with Christ in God.' (Col. 3:3)." St. Simeon the New Theologian You mention God's mercy and Christ's sacrifice and as you can see, the Fathers are with you on that. But sometimes the focus of the West on the clear necessity of God's mercy, man's depravity and the horror of the crucifixion leads to a different view of man's relationship to God than one finds in the East. Oftentimes the Western Church is called The Church of the Passion, while the Eastern Church is called The Church of the Resurrection. Equally valid and important, but different. One of the thoughts which struck me as I read the bishop's piece, is how very hopeful, even joyous it is, how "Do this and you will become like God" instead of "Do this or you will go to Hell" it is. In this sense it is very Orthodox. He must have been a wonderfully holy man.
There is a great deal of joy in being Orthodox.