What does it mean to be a Jew?

I am Jewish by ancestry but not by belief. I call myself Jewish, but I understand that this identification is dependent on the religious beliefs of others. I do tend to stick to the dietary laws out of a lingering sense of guilt. I can’t eat shrimp or ham without all kinds of alarms going off in my head.

At one time the definition of Jewishness was easy. Before Islam and Christianity, Jews were the ones who believed in one god. It may be argued over whether there have been other such religions, but in most places where Jews lived they were the only ones to accept a single god.

Even after Christianity and Islam, Jews could distinguish themselves for a time by the elaborate set of laws and rituals spelled out in the first five books of the Bible.

The problem is that most of those who now call themselves Jewish no longer follow these laws. They may occasionally attend a Sabbath service and go to temple on Rosh Hashanah and Yom Kippur and light candles on Chanukah, but what does this mean? How different are these “observant” Jews from me? Are they not identifying with those in the past who took the laws and rituals seriously?

I address this question in particular to those here who are Jewish, but I leave it open to others to give their opinions as well.