For centuries, people have expressed their religious devotion by building cathedrals, copying sacred manuscripts and launching crusades. Today, of course, they're erecting Web sites.

People of all faiths are assembling temples of devotion on the Net from the Benedictine monks in New Mexico to the Chabad-Lubavitch of Brooklyn. In fact, New York is a hotbed of religion online. Temples, churches and the religious of all types are devoting time and money to building sophisticated sites for teaching the faithful and attracting people outside the community.

They place great faith in the power of this new electronic medium.

"The Internet will be able to unify the entire world to understand godliness," said Rabbi Yosef Kazen, a Brooklynite who labors on the site Chabad-Lubavitch in Cyberspace.

On these religious Web sites, you won't be able to participate in services or go to confession. But they provide inspiration for the faithful and information for the curious who might want to join the flock. ...

About five years ago, Kazen and other technologically proficient members of the Brooklyn-based Lubavitcher Hasidic Jewish community asked their spiritual leader, Rebbe Menachem Schneerson, for his "permission and blessings" to establish a presence on the Internet.

"He said, 'Go for it,"' Kazen remembered, though "not in those exact words."

They started out with free access through Dorsai Embassy, a local nonprofit group that helps other nonprofits get on the Web.

Today, Chabad-Lubavitch in Cyberspace, as the effort is known, is a full-fledged online community.

Kazen volunteers more than 30 hours a week of his time on the site, along with his associate, Elie Winsbacher, with an annual budget approaching $50,000 for equipment, Internet connections and other expenses. They operate out of the Lubavitcher headquarters on Eastern Parkway, complete with a fiber-optic link to the Net.

The site (http://chabad.lubavitch.org/) includes commentary about religious holidays, such as the just-completed Chanukah, essays about Jewish mysticism, a children's corner and a form to fill out that calculates at what time observant Jews in particular cities should light Sabbath candles each Friday night.

Kazen said he started the site after learning of a Jewish woman who was looking for information about prayer but was allergic to paper. Today, he said, the site attracts Lubavitchers and other Jews, as well as Baptist ministers and "average people on the street who want to find out about Judaism."