Most agree the 'Golden rule' is a good moral law. I think that these concepts and beliefs have been imprinted on us by our backgrounds, and that our internal constructs of good are not independent of our Christian background and culture. I think claiming to be part of a group that is more moral than Christians would discredit the source of your morals.
The golden rule is in fact just one of many versions of the 'Ethic of Reciprocity'
It's not unique to Jesus, Christians, or the Bible.
Here's another version: " This is the sum of Dharma (duty / righteousness) : do not do to others what would cause pain if done to you. " ~ Mahabharata - Around 500 B.C
Christians are most definately not the source.