As I prepare to celebrate my first Shavuot as a Jew, I look back on my earlier experiences during this holiday. For 10 years, as a Christian, I regularly attended synagogue and studied with Jewish groups, as well as celebrating most holidays.

As a new Jew, I have a special relationship to Shavuot. After all, the holiday could be described as the commemoration of the conversion of the entire people of Israel, because it marks the day on which Jewish tradition tells us that Moses received the Torah from God on Mount Sinai.

Because the holiday centers around Torah, observant Jews stay up all night in marathon study sessions known as tikkun leil Shavout (literally "Shavuot night repair," alluding to the Jewish goal of "tikkun olam," or repair of the world). Some Jews spend time at a number of different synagogues throughout the night, engaging in a variety of studies.

I've found Shavuot to be an incredible amount of fun, as I do virtually all Jewish holidays. Jewish study sessions rarely spit out facts; rather, they raise endless questions and leave you with a sense of wonder at all there is yet to discover about sacred texts, life, and God. Holiday study sessions dig even deeper, and they're almost always filled with laughter, joy, and camaraderie.

Some years back, I decided to spend my first Shavuot going from synagogue to synagogue, beginning at 9 p.m. and ending with the Shacharit service the next morning, which began just after dawn.

My friend, Karen Prager, and I began the evening at Temple Emanu-El, the synagogue to which I now belong. Rabbi Mark Kaiserman led the first study group. Quips and humor flow from Mark's lips as quickly and readily as seconds pass through a day, and his energy rivals the combined enthusiasm of a room full of second-graders.

That evening, Mark informed us, tongue-in-cheek, that we were going to read the entire Torah. After handing out pieces of paper with the name of each of the parshot (weekly Torah portions) written on them, Mark asked that we silently read the parsha we'd been assigned, then stand and read a single sentence from it in the order they appear in the Torah. One woman sang her portion with gusto, making up her own melody. Some chose verses that plunged the room into laughter; others chose passages that spoke in meaningful ways to many of us.

When we eventually reached Deuteronomy, one man got confused and read a verse from Genesis. About a dozen people knew immediately that he had opened to the wrong book, and several actually knew the precise location of the verse he was reading. Mark didn't miss a beat, jokingly reminding the man that the parshot didn't jump from Numbers back to Genesis and that he'd probably need to stay away from the wine on the refreshment table for the rest of the night. Everyone laughed, including the man who had read from Genesis.

My friend Marc Kivel led the next study session on the book of Ruth, the biblical book traditionally read on Shavuot. Mark distributed Talmudic quotes, Midrashim (rabbinic exegises of the Bible), rabbinical comments, ancient Jewish philosophers' insights, modern Jewish authors' writings, and other scriptural passages that illuminated the one we were studying. One verse into the study and 15 hands shot up. Comments and debates began just another typical night of study with a group of Jews.

A little after midnight, the study session came to a close, and Karen and I headed to another synagogue. A small but intense tikkun was in full swing, led by a Hasidic rabbi with whom I'd studied weekly for several years. After the group warmly and enthusiastically greeted us, the rabbi wanted to know how long we'd be up studying. I answered that we'd there as long as the tikkun lasted. The rabbi was delighted. "Mary is challenging us!" he said, happily.

The rabbi told of a time when no echo existed. "That's because every breath and whisper was the voice of God," he explained, "and all of nature absorbed that voice." For mystical Jews, nothing in Torah or in all of life remains merely on a pshat, or literal, level. When you approach the Torah, the rabbi explained, you can go through 10,000 levels, and 10,000 additional levels are inside each of these. Those able to go deep enough will come to the level of sod, the final level of understanding of the text that reveals secrets and mysteries behind the sacred teachings. Here one enters the mystical world of atzilut, where some Jews believe that we pass beyond the intellect, into union with God.

At around 2:30 a.m., Karen headed home, and I drove to Tiferet Israel, a synagogue affiliated with the Union for Traditional Judaism. One of my friends, Jeff Abrams, was leading a discussion there with a group of teenagers, and I listened in for an hour or so. It had been less than a year since the 9/11 tragedy, and the teens were deeply engaged in a struggle to deal with the hatred that had reared its head in such a hideous way.

My last stop was Shearith Israel. There, several people were talking and studying as if the evening had just begun. Some made frequent trips to the snack table to refill their coffee mugs and grab a handful of nuts. Others slept sitting straight up, and at least one person had retired to the couch, making no pretense of trying to stay awake.

A man handed me a copy of Psalm 148, in which all of nature, humankind, and even the heavenly bodies cry out in praise to God. As soon as the rabbi finished reading it, everyone jumped in. "The psalm reflects the order of creation from the sun and moon to animals," one man said. "Every animal, person, and aspect of nature is commanded individually to praise," observed another, "then suddenly there is one single command to everything and everyone to praise. That's an indication that we progress from separateness to unity."