The definition of what is considered good and who thinks a person is good can be very relative, vague and elastic.
A person who attends religious service and doesn't break laws is not necessarily good. No more than a person who, in a moment of weakness and desperation, robs and breaks the law is bad. An extreme example, granted.
Someone who believes in a Supreme Being is not deemed to be 'good' or 'right'- they just believe a certain specific way that doesn't dictate what the rest of their morality or 'goodness' is.
Someone who doesn't believe in a Supreme Being is not bad, they just follow a certain specific belief system. Non-believers can be quite upstanding, moral and dedicated citizens. And they also may not be - just as Theists are, too.