The Atlanta metro area has more than 40 Jewish congregations. I never like to use an exact number for fear of overlooking an emerging kehillah (community) as Atlanta grows in all directions.

But the exact number now isn’t nearly as important as the exact number 50 years ago: six. We had The Temple, Ahavath Achim, Or VeShalom, Anshi S’fard, Shearith Israel and newcomer Beth Jacob (then only 25 years old).

Put another way, six times as many congregations have opened and endured in the past 50 years as opened and survived through the previous 101 years of Jewish organization in Atlanta.

The beginning of that seemingly unending boom — post-Six-Day War? post-Tet Offensive? post-MLK and RFK assassinations? — was the opening of Temple Sinai, Atlanta’s second Reform congregation, in the fall of 1968.

The congregation is celebrating all year, as befits a jubilee.

Special Friday night services — recognizing, for example, people having a 50th birthday or a 50th wedding anniversary in 2018 — will be held monthly.

Special events include Sinaistock for a groovy Purim in March, the “Saturday Night Live”-inspired Sinai Night Live in April, a family carnival in August, a mitzvah day in October and a gala finale in November.

Bunzl Family Cantorial Chair Beth Schafer

Sinai launched its yearlong jubilee with a Friday night celebration Jan. 19, which doubled as a 50th birthday party for Bunzl Family Cantorial Chair Beth Schafer, who composed a song, “HaYashan Yitchadesh,” for the occasion.

The night included an overwhelming dinner for 480 people miraculously crammed around circular tables in the social hall, where a faux time capsule from 1968 was opened. It included stock in Eastern Airlines; a congratulatory note from that year’s Heisman Trophy winner, O.J. Simpson; and a written promise from former Sinai President Arthur Heyman to make a $50,000 donation if the congregation survived 50 years.

The Kabbalat Shabbat service before the dinner drew about 800 people, forcing the kind of satellite-parking/shuttle-bus setup usually reserved for the High Holidays and inducing pre-thaw jokes after three days of canceled school about climate change producing snow on Yom Kippur.

Sandy Springs Mayor Rusty Paul

Sandy Springs Mayor Rusty Paul, whose city formed around Temple Sinai 37 years after the congregation was born, offered congratulatory remarks from the bimah to start the service. Rabbi Rick Jacobs, the president of the Union for Reform Judaism, overcame a week of frigid Southern weather and Delta Air Lines cancellations to deliver a sermon celebrating a congregation he described as a leading light of his movement.

Temple Sinai began with 30 people; it now has roughly 1,400 families. But the raw numbers don’t reflect its true impact.

It has launched or helped found food rescue organization Second Helpings, homeless support group Family Promise and Sandy Springs’ Community Assistance Center. It likely has more members on the national Union for Reform Judaism board than any other congregation, Rabbi Jacobs said. Its senior rabbi, Ron Segal, is the president-elect of the Reform movement’s Central Conference of American Rabbis.

As Rabbi Jacobs said, Temple Sinai “attracts leaders, grows leaders and shares leaders.”

Now it gets to lead a rising wave of similar, if smaller, jubilees at Atlanta congregations in the next 15 to 20 years.

Schafer’s new song perhaps said it best, for Sinai and for Jewish Atlanta as a whole: “Let’s give thanks and dream again/What we do is never done/The blessing is the journey/A new day has begun.”