If I'm an atheist, does that make me a bad person? I believe strongly in the validity of the scientific method. I teach my children to approach the world from a scientific perspective, and I also try to instill in them deep-seated principles of compassion, kindness, generosity, and sensitivity to others. Does that make me a "sinner"?
The answer to your question is "yes and no." Are you a "bad person" because you are an atheist who teaches his children to think scientifically and to practice principles of kindness and compassion? Obviously not. Scientific principles are extremely valuable and helpful. As for kindness and compassion, they come straight from the heart of God – in fact, the apostle Paul includes them in his description of "the fruit of the Spirit" in Galatians 5:22. Based on what you've told us so far, we'd have to say that you sound like a committed father and a responsible member of society. As for your lack of faith in God … well, that doesn't make you any "worse" than anybody else. But more on this in a moment.
Are you a "bad person" despite the fact that you're an involved father, an upstanding citizen, and an atheist who teaches his children scientific principles? If we frame the question this way, there's an important sense in which orthodox Christian theology requires us to say yes. The Bible tells us that every individual ever born is a "bad person." That includes the best, the bravest, and the most saintly among us – people like Florence Nightingale and Abraham Lincoln and Mother Teresa.
"There is none righteous, no, not one," writes the Psalmist (Psalm 14:1-3). "All have sinned and fall short of the glory of God," says the apostle Paul (Romans 3:23) – who, by the way, refers to himself as the "chief of sinners" in 1 Timothy 1:15. The good news in the midst of all this is that God loves us in spite of our sin and has sent His Son Jesus Christ to purchase our redemption. This is what the Christian message is all about: we are all sinners, but we can all be forgiven and born anew through faith in Christ.
If you'd like to know more about this, Focus on the Family has a staff of pastoral counselors who would love to speak with you over the phone.