It's fairly easy to have a good, consistent morality without belief in a supreme being/supreme beings and an objective morality. All it takes is empathy - the ability to understand that others have feelings and thoughts like you do, and that they should be treated by you the same way you'd want them to treat you. That there's no difference between whether it's you hurting them or them hurting you. Then just a little nudge more by the realization that not everyone likes and dislikes the exact same things.

At that point, it's very easy to treat others with fairness and respect. A morality based on that is a very good one. It won't cover all issues, but then again, there isn't an existing one that does.

If you are only following a morality because of the threat of punishment, whether here or in a theoretical afterlife, then you aren't a moral person. True morality is not killing because it's not right, and not just because of fear of jail or hell.