Orthodox: mercy, justice and a Redeemer

  I've been reading in an old Russian Orthodox systematic theology.  The purpose is to learn, specifically about what has been believed by those who have lived in this area under Christ's name longest.  In this particular instance, the quotation also speaks to the majority beliefs locally. So here, from the sections about sin and salvation is a beautiful expression:

In regard to repentance also, it can never be sincere in the corrupt and unregenerate heart; because, to the end of life, the perpetual commission of sin proves it to be weak and ineffectual; for former acts of repentance, are ever violated by present transgressions. I do not mean evangelical or Christian repentance; it is of another kind: and why it is effectual, we shall soon show.

Let no man, however, suppose, that because God is infinitely merciful, or rather mercy itself, he can, without regarding men's imperfections and their falling into sin, out of his mere goodness, pardon men, and render them fit to be partakers of his blessedness and glory. Such reasoning is base and sinful; it makes the mercy of God blind; it presupposes a God not possessed of eternal and inviolable rectitude. It obliges him to regard the righteous and the wicked alike, a supposition which it is dreadful to apply to the living God. 

Does any one ask, by what way then can man be saved? By that way, I answer, which infinite wisdom has devised, and in which the mercy of our God is united with a full satisfaction of his justice, in the work of our salvation. And what this way is, the word of God has particularly revealed to us. (pg128)

(...)

The love and mercy of God to all his creatures, but particularly to man, is greater than we are capable of comprehending. How could that Being then, whose goodness transcends our comprehension, suffer man, the chief among the creatures, to perish; and who, according to the design of God himself, was created for eternal happiness? But the justice of God is no less real than his mercy, and could not suffer the least violation. Thus, if anywhere, more especially here, we must use the words of the gospel: "The things which are impossible with men, are possible with God." (Luke 18:27) What can be hid from the infinite wisdom of God? To it, the most secret means are all open and revealed. It beheld, that on the part of man there was no way by which he could obtain salvation; because every individual stood in need of this for himself. The angels were not possessed of adequate powers to execute this great work, which required nothing less than infinite might. There remained no hope but in God himself. And hence, in the most secret counsels of the Holy Trinity, which are impenetrable to the powers of angels, it was appointed, that the most exalted Son of God should himself become the Redeemer of the human race, and this office he assumed.

(pg 130)

- Platon, A Summary of Christian Divinity 

("Man is unable to deliver himself" and "For the salvation of man, God himself became incarnate" sections)