"You don't have to be a Christian to be a good person." – Ray Comfort<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

A Christian is not a "good person." How can anyone be called a good person when we have no clear definition of the word "good"? Is a rapist a good person because he no longer rapes? Or does a thief become a good person when he gives to charity? Some would say "Yes," and others would say "No."
The only way to define who is good and who isn't is to define the word "good." The dictionary lists 58 definitions, but the principle meaning is to be "morally excellent." In God's view, to be "good" means to be morally perfect, in thought, word, and deed. The Bible tells us that only God is good (see Mark 10:17). Even the word is derived from the word "God." So, once we have a clear definition, it is obvious that a Christian is not a good person. Neither is a non-Christian.
It is true that you don't have to be a Christian to live a good life. Anyone can do the things that Christians do. They can open hospitals, establish schools, feed the poor, build houses, etc. But that won't get anyone to heaven, nor will it save anyone from hell. This is because salvation has nothing to do with our "good" works. How could it? What could you and I ever do to "earn" everlasting life?
But add the fact that we are criminals, having violated the Law of a holy God a multitude of times, and it becomes clear that the only way any of us could ever be saved from hell and enter heaven is by the mercy of the Judge. And that is what the Bible teaches. A Christian is saved by the grace and mercy of God, without works: "For by grace are you saved through faith; and that not of yourselves. It is the gift of God, not of works lest any man boast" (Eph. 2:8,9).
So, stop pretending to be good, and realize that doing good will do you no good on Judgment Day. Instead, repent and trust the Savior, and then live a good life-not to impress anyone or bribe God, but out of gratitude to Him for His mercy.
Proverbs 20:9 Who can say, I have made my heart clean, I am pure from my sin?