Are good, nice, or church-going people still sinners?
Good people, nice people, and church-going people are still sinners, because all are guilty of breaking God's perfect Law. The Law is what condemns them, not their moral goodness or church attendance. Being decent or religious does not remove guilt; the old sin nature still breaks God's law.
Les teaches that good people, nice people, and church people are still sinners because all are guilty of having broken God's perfect Law, and the Law is what condemns us. He then points to Romans 7, calling it tough and comparing it to 8th grade arithmetic story problems that boggle the mind before the answer comes out. In Romans 7, beginning at verse 7, Paul asks whether the Law is sin and answers, "Banish the thought." Paul says he would not have known sin—that is, the old sin nature—except by the Law, nor known lust except the Law said, "Thou shalt not." Thus the Law condemned this religious Jew who thought he was keeping it, while sin, his old sin nature, took occasion by the commandments and wrought in him all manner of contraptions.