The last verse of Jeremiah 31:29, and sets forth fully the doctrine of individual responsibility.
Matthew Henry
Concise Bible Commentary
The soul that sinneth it shall die. As to eternity, every man was, is, and will be dealt with, as his conduct shows him to have been under the old covenant of works, or the new covenant of grace. Whatever outward sufferings come upon men through the sins of others, they deserve for their own sins all they suffer; and the Lord overrules every event for the eternal good of believers. All souls are in the hand of the great Creator: he will deal with them in justice or mercy; nor will any perish for the sins of another, who is not in some sense worthy of death for his own. We all have sinned, and our souls must be lost, if God deal with us according to his holy law; but we are invited to come to Christ. If a man who had shown his faith by his works, had a wicked son, whose character and conduct were the reverse of his parent's, could it be expected he should escape the Divine vengeance on account of his father's piety? Surely not. And should a wicked man have a son who walked before God as righteous, this man would not perish for his father's sins. If the son was not free from evils in this life, still he should be partaker of salvation. The question here is not about the meritorious ground of justification, but about the Lord's dealings with the righteous and the wicked.