A couple of nights ago, the Vespers readings included the account of Cain from Genesis 4. The SAAS (Septuagint) translation in the Orthodox Study Bible reads:

The Lord respected Abel and his offering, but He did not respect Cain and his sacrifices. So Cain was extremely sorrowful, and his countenance fell. So the Lord said to Cain, “Why are you extremely sorrowful? And why has your face fallen? Did you not sin, even though you brought it rightly, but did not divide it rightly? Be still; his recourse shall be to you; and you shall rule over him.”

Now Cain talked with Abel his brother and it came to pass, when they were in the field, that Cain rose up against Abel his brother and killed him. Then God said to Cain, “Where is Abel your brother?” He replied, “I do not know. Am I my brother’s keeper?”

Thus God said, “What have you done? The voice of your brother’s blood cries out to Me from the ground. So now you are cursed from from the earth, which has opened its mouth to receive your brother’s blood from your hand. When you till the ground, it shall no longer yield its strength to you. You will be groaning and trembling on the earth.”

Then Cain said to the Lord, “My guilt is too great to be forgiven! Surely You have driven me out this day from the face of the ground; I shall be hidden from Your face; I shall be groaning and trembling on the earth. Then it will happen, if anyone finds me, he will kill me.”

So the Lord God said to him, “Not so! Whoever kills Cain, vengeance shall be taken on him sevenfold.” Thus the Lord set a sign on Cain, lest anyone finding him should kill him. Then Cain went out from the presence of the Lord and dwelt in the land of Nod* opposite Eden.
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*(“Nod” means “one who wanders away from God”)

I’m impressed with both Cain’s awareness of how he’s broken fellowship with God, and God’s compassion toward him. And there’s the promise God offers Cain that, if he’ll be patient, Abel will come to him and serve him, if he’ll only wait and trust. Repentance and restoration are always available to Cain; but he can’t believe he can be forgiven. So he walks away from reconciliation.