Your assumptions are foolish.
Golden rule and variations that predate the NT are all religious based.
In other words, there is a trend I see here which is that the morality espoused by atheists is always the same as something all ready existing that came from a very old religious position.
The obtuseness is hilarious.
Religion was man's first crack at philosophy. So any sort of moral philosophy prior to modern science is likely to fall under some sort of religion. You don't get a Nobel Prize for figuring that out.
You're missing the obvious point here, which is that the Golden Rule seems to have some sort of corollary in all cultures worldwide, which speaks to it being ingrained in humanity, not dictated from whatever imaginary gods or goddesses. Also, calling Buddhism and Confucianism "religion" is a stretch.
How do you define morality?