Yom Kippur, the holiest day of the year for Jewish people and marked by 25 hours of fasting and deep prayer, starts Tuesday night at sunset.
Culminating the High Holy Days that began with Rosh Hashanah 10 days earlier, Yom Kippur is a time of intense self-reflection, when Jews examine their lives and think of how they can improve, said Rabbi Zev Friedman of the Congregation Rambam Mesivta in Lawrence.
"It's really a solemn day, focusing on prayer and trying to make things better," he said.
The faithful abstain from food, liquids and anything else that gives pleasure, he said. "You have to realize comforts are not the main thing in life," he said.
He said the self-reflection might even include things such as people realizing they are too angry or jealous in nature, and trying to rectify that.
Friedman and some other Orthodox rabbis also said they will make Iran's alleged efforts to obtain nuclear weapons a central part of the talks at their services, which end Wednesday at sunset. Iranian President Mahmoud Ahmadinejad is expected to address the UN General Assembly that day.
The Manhattan-based Orthodox Union and the Rabbinical Council of America have issued a call for synagogues to use the Yom Kippur services to denounce Iran's "evil regime" and its threats to destroy Israel.
"Israel is in our hearts every year, no matter what," said Rabbi Ira Ebbin of Congregation Ohav Shalom in Merrick. "But when it comes to this year, there is an anxiety and a concern that can't be ignored."
But Rabbi Steven Moss of B'nai Israel Reform Temple in Oakdale said that while Iran is a concern, he will keep the focus during Yom Kippur on the faithful's personal reflections. "My goal is to effect a change in people's lives, or find a direction in their lives," he said.
He added that he plans to talk about "the importance of finding meaning and purpose in our lives to help us through the difficulties" people often encounter.