The semi-monastic jewish community during the roman period that referred to themselves as the "sons of light" were

They were the Essenes

They were a religious sect based on Second Temple Judaism and lived in Judaea in high numbers. They were semi-monastic insofar that they lived in voluntary poverty, were highly ascetic, often they practiced complete celibacy, and they were also known for their daily practice of immersion. They were found to live in areas around the Dead Sea.