Atheism is too bracing a truth to offer needed comfort to grieving people. That explains why religion continues to have such a hold on humanity. The Hindu ceremony is no more valid than a Christian funeral service, because there really is nothing after death. But I do understand why Stallone would seek out ways to find comfort.
How do you know there's nothing after death? Have you been there and back? Rabid atheism is as stupid as rabid religiosity. I would leave individual souls to seek out their own truth, whatever that turns out to be.
"My religion says apostasy is a crime punishable by death. So if someone from my faith says they no longer believe, they must be killed."
"My religion says this path is the only way for your soul to be saved. So because I love you and want your soul to be saved, I will disparage your faith and try to convert you to mine."
"My religion says the cow is holy and eating its meat is a sin. So I am justified in lynching you because I think you may have eaten a cow's meat."