Amen, it is about belief, even what one believes in the heart.
I don’t know about some unbelievers being better than some believers, though. I have to think it’s more a matter of appearances to us, who only see in part in this life. A believer is, at bottom, a just person while an unbeliever is, at bottom, an unjust one, and that will be expressed in what they do, even if it’s not really entirely visible to us.
I’ve used this comparison for a few decades:
Imagine a guy that was taught by his parents to be good and treat people with respect and help the poor. On a scale of 1-10 in goodness he may be a 9. Now imagine another that was the son of a crack mom, raised by his grandmother that was a prostitute and is also usually on some kind of drug and alcohol. He joined a gang and does a lot of beating people up, robbing, etc. He is a 1.
Now, the latter accepts Jesus as his savior and, through reading, training and prayer, he becomes a 6 before he dies. Meanwhile, the former never accepts the Lord and, though he may do a lot of good for people through tax deductible donations, etc. he drops to an 8 on the goodness level - i.e. how he treats others, etc.
So, from the world’s perspective, he’s a “better” person. But that has nothing to do with eternity. Rather, the one that believes has received eternal life, while the one that is “better” will live the Ecclesiastes life: Eat and drink and enjoy the fruits of his labor, and then his body dies, like the rest of the animals. And the only difference between him and the rest of the animals is he has a human soul - the person - who dies. It’s called the second death.