That's right, another example for this theme is the parable of the Unmerciful Servant (Matthew 18:21-35), who had liabilities and gets the Grace of his Lord, but didn't forgive his servant who had liabilities by him, what his Lord saw and punished him after that (just who forgive others will get forgivness for his sins).

Another passage which seems to be very important is "Matthew 25:41-46", because this passage describe so called Christians who you've mentioned too, people, who just made a lip service, but started to refuse to follow Jesus Christ (Matthew 25:41-46).