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Some years back, when my sister was dating a non-Jew, the first Jewish service she took him to was a Purim celebration. His reaction was "This is religion?"

Her answer might well have been, "Yes, this is Jewish religion."

Though Jews sometimes have a hard time explaining it to people of other faiths, in our religion, culture and faith are inextricably mixed. That's partly because of the kind of faith we have: not faith in a particular understanding of God, but in a particular understanding of human beings, of what life is for. This is especially clear on the carnival holiday of Purim, which begins Wednesday evening.

In Christianity, there is a clear separation between faith and culture. The cultures of Christians are diverse; their common faith unites them. Mardi Gras is a custom in some Christian lands; Easter is a holiday of faith common to virtually all who consider themselves Christians.

Jews, too, have lived in many lands and many cultures. But we have also carried with us our own religious culture connecting us to Jews in other times and places.

Because the central "character" in the Jewish story is a people, not a person, every holiday is part of a celebration of that common history. The story that we read from the Megillah, the special scroll for Purim, is about one clever queen, Esther, saving her people from the plot of one evil persecutor, Haman, and one stupid king, Ahasuerus, in one ancient kingdom, Persia.

But it is more: It is about the persecutions we have endured — and survived — because we dared to remain different, loyal to our own culture and values, in the many lands where we have lived. Even Yom Kippur, that most abstract and "religious" of Jewish holidays, also remembers the persecutions we have faced down as a people. The Kol Nidre chant with which we begin the holiday recalls the many times we have been tortured into swearing allegiance to something we didn't believe in. It affirms that we will and must do what we can to survive both physically and spiritually — to continue to live, and live morally, and to live as Jews.

In addition to history, all Jewish holidays have another story to tell — the story of the human spirit as we understand it. Purim celebrates silliness, cleverness, adaptability and simple stubbornness: the human ability to out-maneuver tyranny through wit, terror, through laughter. Yom Kippur, in its solemn baring of the soul, celebrates the opposite side of human nature — our ability to take things seriously, to be utterly honest, to respond with the depths of our being. The rabbis recognized the intimate connection between the two holidays: they called Yom Kippur "Yom HaKiPurim," the holiday that is like Purim. The rabbis said that after the Messiah comes, Purim is the one holiday Jews will still celebrate.

The ability to laugh is fundamental to being human — and when all other differences among human beings are gone, when humanity is truly one, laughter will remain, to unite us.

All Jewish holidays celebrate some aspect of the human experience. Passover, in the spring, celebrates the hope and joy of freedom. Tisha B'Av, in the dead heat of summer, commemorates the destruction of the Temple, the dashing of hope, the loss of freedom, and the accompanying cruelty, horror and despair. Sukkot in the fall celebrates our connection to the earth, to fertility, to simple physical happiness. Shavuot, in late spring, is also a harvest holiday, but how different: It celebrates Sinai, the capacity for revelation, commitment to a higher ideal, sacred covenant.

Taken together, the cycle of Jewish holidays comprises a history and celebration of the full range of the human spirit.

Acknowledging the ups and downs, the bitter and the sweet, Jews through their holidays affirm that as individuals and as communities we can make our lives count for something, no matter what fate the world imposes upon us.

Yom Kippur is the holiday when, if ever we can, we open ourselves to connection with God, to some higher force within or beyond ourselves that can help us to surpass our worst and seek our sweetest and sanest selves. Purim, as Rabbi Irving Greenberg points out in his book "The Jewish Way," is a holiday where God seems quite hidden. At Passover, only God and not Moses is mentioned in the Haggadah, to make it clear that God and not Moses is the One who brought us out of Egypt. But in the Purim Megillah, it is up to Esther and her cousin Mordechai to perform the miracle, that miracle of stubborn courage, cleverness and resilience that has enabled the Jews to survive so much.

If you get a random selection of Jews together, you are likely to get substantial, even bitter, disagreement on whether there is a God, let alone what God wants of us in the way of Jewish observance. But you are likely to find a surprising depth of agreement on something else: It's important to make a difference with your life, to make the world a better place. That's the most important element of faith that Jews bequeathed to our daughter religions, Christianity and Islam. And it's what united holidays as different as Purim and Yom Kippur.

On Yom Kippur, we rededicate ourselves to living our lives as morally as possible. On Purim, we agree that, whether we see God's presence in our lives or not, it's important to laugh a little, cry a little and do the best we can to make life possible for one another.

Are the two messages really so different?