The average person thinks he is going to heaven because he is "a good person." But what does that mean, and how "good" does a person need to be to go to heaven?

Jesus was asked once by a rich young ruler, in Mark, chapter 10, "Good Master, what shall I do to inherit eternal life?" (Mark 10:17).

Jesus had a surprising response, "Why callest thou me good? There is none good but one, that is, God" (Mark 10:18).