The real tragedy is that those who mix faith with good deeds and are hoping to receive pardon through their good deeds, will be found guilty for failing to keep the Ten Commandments and be sentenced to God's eternal prison without parole. The only Person who will be able to give them a pardon will be Jesus Christ, and He will give it only for those who put their full trust in God's grace and mercy through a total trust in Jesus through faith.
It is like a person who comes before a judge charged with rape. He might tell the judge that although he is guilty of rape, he has done many good deeds since, like helping the poor, running a homeless shelter, working for the church, caring for orphans, etc. But the judge will say, "You are before me on the charge of rape, not for the good deeds you have done, therefore you have to be sentenced to prison for rape". In this way, because we have all broken the Ten Commandments by, at times in our lives, have lied, stolen, blasphemed, and looked at people with lust, we will be found guilty of being a lying, thieving, blaspheming, adulterer at heart, and our good deeds won't help us avoid the inevitable sentence of incarceration in God's eternal prison without the possibility of parole.
That is the real tragedy for those who are depending on their good deeds mixed with faith, to get them through the judgment without being sentenced to hell for their sins.