“He died for all, that those who live might no longer live for themselves but for him who for their sake died and was raised.”
Did you know that living for yourself is a sin?
It seems a little harsh when we think of it that way. We think of sins as major patterns of observably evil behavior, and the word of God even leads us in that direction: “Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor men who practice homosexuality, nor thieves, nor the greedy, nor drunkards, nor revilers, nor swindlers will inherit the kingdom of God.”
These are not oopsies, slips, errors or one-off sins. We can forgive those in ourselves easily enough. No, Paul is talking about ongoing patterns of behavior that become more important to people than obedience to Christ. These are the things that keep men and women out of heaven.