What makes someone a "good" person? Maybe you'd say someone who obeys the laws or someone who is considerate and kind to those around them. If you wanted to go a bit deeper than that, you might say someone who goes out of their way to care for others, especially those who can't care for themselves, or someone who lives with integrity even when no one is watching.
Are any of the actions mentioned above bad? No! Are they good? Yes, of course! I don't think there's anyone that would argue against that. However, does doing good things make you a "good" person? I would argue that it doens't, nor does doing bad things make you a "bad" person.
I think this is a critical thing to understand from a Christian perspective. The world may group people as "good" or "bad" based on their attitudes, words, and actions. However, I believe that we, as Christians, ought to see people and ourselves from a different perspective. The world judges people based on the external things that they produce, but we are to judge people based on nothing but their inherent value as human beings. For, if we judge based on the world's standard or, dare I say it, based on a religious standard, doesn't that defeat the purpose of the Gospel? If we can be "good" or "bad" people based on our works alone, why do we need God?
I'm not saying it's never appropriate to judge. I do think we, as Christians, can and should judge attitudes, words, and actions based on God's standard. I do certainly believe that there is objective truth and clear lines between right and wrong in many situations. But, I think it's critical that we separate the attitude, word, or action from the person. We should identity people with who God says they are, not with how they behave on a certain day. Everyone does the latter. We can distinguish ourselves as Christians and display the remarkable grace and love of God by doing the former.
"No one is good-- except God alone." (Luke 18:19) We shouldn't group ourselves into the camps "good" or "bad." We are all just people. The only real difference between us is that some of us have experienced the life-changing power of the Gospel and some haven't. And, that isn't the result of anything we did. That was all God. Therefore, we have no reason at all to look down on our fellow man. Anything good in us is the result of God's abundant grace.