Tucson’s Congregation Bet Shalom has quadrupled in size since 2012. That’s when Avi Alpert came on board as its spiritual leader, first as a cantor and later as a full-fledged rabbi. Congregants attribute the change to Alpert, whom they describe as “incredibly approachable” and “very open-minded, but very strong in his identity.”On Sept. 20, Bet Shalom will honor the rabbi at a Kiddush lunch. In addition to “official Bet Shalomers,” he says, the congregation has hundreds of “friends of Bet Shalom” who often contribute generously and participate in the life of the congregation. Mizrachi, the rabbi explains, is one of several Jews who have moved to his neighborhood, which is walking distance to Bet Shalom.