At 12:50 p.m. on Friday, June 26, at the corner of Malcolm X Boulevard and Tremont Street in Roxbury, Massachusetts, a ribbon was cut, marking the official opening of the largest mosque in New England. More than a thousand Muslim faithful attended the event, and Mayor Thomas Menino spoke words of welcome. That morning, at the inaugural breakfast held across the street, the dean of Harvard's Divinity School gave the keynote address. By videotaped message, Gov. Deval Patrick offered warm greetings. The large hall was filled, including city and state officials, Muslim, Christian and Jewish clergy, academics and leaders and members of assorted community groups. Conspicuously absent were officials of what are commonly referred to as the "mainstream Jewish organizations." Their absence was described, in Boston Globe religion columnist Michael Paulson's blog, as a "boycott." Why the apparent "boycott"? The answer, it seems, is that these organizations are uneasy about the true character of the groups directly connected with the mosque: the Islamic Society of Boston Cultural Center (ISBCC) and the Boston chapter of the Muslim American Society (MAS-Boston). These concerns were reflected in leaflets handed out by a small group protesting the inaugural celebration, claiming, for example, that US prosecutors have identified MAS as "the overt arm of the Muslim Brotherhood in America," citing financial backing by Saudi contributors and alleging ties to terrorism or offensive remarks by individuals with either a past or present connection to the mosque. ARE ISBCC and MAS-Boston likely dominated by Islamist extremists, and hence properly boycotted by Jewish - and other - groups? My own personal experience suggests strongly to the contrary. In the past three years, as an individual, and as an officer and representative of a Jewish communal organization, in my dealings with leaders of both ISBCC and MAS-Boston, I have encountered only graciousness, sincerity and warmth. I have also observed these leaders demonstrate the same attitudes and behaviors toward rabbis and lay leaders of an array of Jewish organizations. At least as noteworthy are two public statements crafted collaboratively with ISBCC and MAS-Boston leaders. The first, "Building a Community of Trust," was rolled out in 2007 at every mosque in Greater Boston on the first day of Ramadan, and at synagogues on Rosh Hashana. Announcing the stated goal of replacing distrust and misunderstanding with respectful communication, the Muslim and Jewish signers expressly decried all forms of terrorism, anti-Semitism and anti-Muslim prejudice. The signers - imams, rabbis, and Jewish and Muslim community leaders and members - embraced a Greater Boston in which diversity is respected, and pledged to foster efforts to decrease divisions between our communities. From what I have observed, MAS-Boston and the ISBCC have acted in a manner consistent with those principles. Even more striking, perhaps, is an interfaith declaration that was born during the hostilities in Gaza in January 2009. Drafted and signed by Jewish, Muslim and Christian clergy and lay leaders - including, again, MAS-Boston and ISBCC leadership - the statement acknowledged the painful history of the Israeli-Palestinian conflict for both sides. It deplored any invocation of religion as a justification for violence against others or the deprivation of the rights of others, and decried any use of inflammatory rhetoric that demonizes the other and promotes hatred and disrespect. Calling on Hamas to immediately end all rocket attacks on Israel, and on Israel to end its Gaza military campaign, it urged all parties to work vigorously toward a just and lasting peace that promotes the national aspirations of both the Israeli and Palestinian peoples. Are these statements - together with much other interfaith work in which MAS-Boston and the ISBCC are proactively engaged - merely a ruse to camouflage their true extremist intentions? Are the leaders of these groups really fanatics in moderates' clothing? I think not. All groups participating in civic life in the United States need be vigilant in addressing the elements among them that foment hatred and disrespect for the other. In my experience, MAS-Boston and the ISBCC have taken this challenge seriously. But to the extent Jewish or other organizations remain concerned, surely respectful, open and honest engagement - consistent with the letter and spirit of the declarations cited above - will prove more effective than boycott in moving us all forward. The writer is an attorney and president of Boston Workmen's Circle, a 110-year old communal organization dedicated to secular Jewish education, culture and social justice.