"Do not call to mind the former things, Or ponder things of the past." (Is 43:18) People will make mistakes. Perhaps they're terrible mistakes—maybe you know someone who has cheated on a spouse in the past, even.
People cannot effectively overcome if we remember them as they once were; if we keep them trapped in the past. Imagine if we only saw Christ dying on the cross and never admitted that YES, He rose from the grave. Let's be like God, who said, "For I will be merciful toward their iniquities, and I will remember their sins no more.” (Heb 8:12)
Help people get past the past. Don't keep them stuck in their past mistakes.
"For the entire Law is fulfilled in in this one word: "You shall love your neighbor as yourself."—Gal 5:14