“When the son has done what is lawful and right, and has kept all my statutes, and has done them, he will surely live. The person who sins, he will die. The son will not bear the iniquity of the father, nor will the father bear the iniquity of the son, the righteousness of the righteous will be on him (the righteous one), and the wickedness of the wicked will be on him (the wicked one).”
God's reply was that each will be judged on his own merits, on the basis of what he reveals himself to be by his life. None will be condemned for the behaviour and attitudes of another. He who honours God and obeys His commands will live. He who by his sin and by his life reveals that He despises God and His ways will die.
Once again the words go deeper than mere life and death, containing some idea of quality of life as well as awfulness of judgment. ‘The one who has done right will surely live, -- the one who sins will die.' The sinner will die in himself before he finally faces the judgment, and then the judgment will lie before him, the dreadful end, the judgment of death and dishonour. While the afterlife was as yet an unknown doctrine some trace of it lies behind the words, an instinct not yet put into words, although Daniel would enunciate it in Daniel 12:2-3.
‘The son will not bear the iniquity of the father, nor will the father bear the iniquity of the son, the righteousness of the righteous will be on him (the righteous one), and the wickedness of the wicked will be on him (the wicked one).' The contrast is deliberately stark in order to establish the principle. It ignores the shades of difference that would arise the levels of righteousness and wickedness. It was the principle that mattered. Each is responsible for himself and will receive accordingly.
Elsewhere it would be revealed that the fully righteous would only be so because of the activity of God in their lives, for none were fully righteous in themselves. But here that was not under consideration. What was in question here was the basis and fairness of the judgment of the God who held each responsible for himself, and judged each one face to face only for his own sins.