"Conscience and morals are perhaps built into us, in the same way that pack animals look out for each other."

So is aggression. There are evolutionary advantages to both cooperation and competition, as there are to both compassion and aggression. To a certain degree, the capacity for religious belief may be built into us as well.

"Religion however is a man made abstract"

All moral codes are "man made abstract" in their specific details. Religious beliefs are simply moral codes with an overlay of the supernatural.

There is no definable distinction between between religious beliefs and moral conscience, and in practice they often blur together. Look into to the beliefs of Quakers and Buddhists if you need examples.

All moral codes and religious beliefs are subjective in this way. I believe it is right for society to look after the weak, but I can't offer objective proof for my beliefs. My beliefs developed out of my religious training, but while my faith has faded my beliefs remain.