I am not saying there is no quality in being a good person without God, but I am sure, all things considered, that a good person, can only become more good after meeting Jesus.
For whatever it may be worth, I was for a long time a Scout leader. A significant fraction of our scouts came from religious families; some went to religious schools, some were even from evangelical families. As far as I could see, those scouts were entirely indistinguishable from the others in terms of honesty, kindness etc.
One might object that the scouts were still young. That's true, but I always found that one could have deep, even complex conversations with them (typically on the trail somewhere), and that their intellects were not to be despised at all.
I rather doubt that religion has much effect on morality.