I'm super drunk right now, so sorry if this is incoherent schizo babble. Also I know this was last posted on 2 years ago but I wanted to chime in, so sorry in advance for the thread necro.
People can be good without nihilism or religion. goodness comes from the heart and the quality of the person. Nihilism justifies hedonism, which easily justifies atrocities conducted towards the human race. If one does "only what feels good", then inevitably there will be those who use such weak moral justification to continue their own crimes against people; whether they are aware of it or not. For take the man who simply goes along with a corrupt and evil government or institution, one who refuses to fight back. Either he is fearful or he is in the mindset of "let people enjoy things", in either case he is allowing evil things to happen around him. Simone de Beauvoir, a famous existential philosopher and known communist, would call these types of people a "useful idiot". They would follow the rules and actions of those above them, blindly follow ideologies, and be a servant to "something greater". Hedonists and nihilists fit this role so well in the modern age it's a shame they aren't recognized as some sort of cult. They follow the words of "science" (or those that take bribes from corps or governments to confirm data that benefits their contractors) and refuse to do any research themselves. They are the antithesis and a mockery of the scientific method and should be ashamed of themselves.
On the other hand religious teachings do not make a man a better person. They can lead to salvation, for they are the teachings of our ancestors, but blind faith makes you nothing more than another useful idiot. It is through critical thought, an open mind, and a love of those around you that allows you to fully grasp what the teachings of many religions attempt to convey. Religion is a personal journey towards truth and salvation, and we all find something different at the end. Sometimes we take this journey again from the start, other times we never walk the path of discovery again.
It is neither religion nor science alone that makes someone good. It is the paths they walk and the conclusions they come to that allows you to know if they are moral or not. Some people are still in the middle of their journey; others need to look upon the world with a fresh perspective. there is good in all, they just need time to realize it.