Santa Rosa's Adventist Church annually provides a living nativity on the church grounds.  Complete with colorful costumes, Joseph, Mary and a baby Jesus, the renewal of hope each year is born during the Christmas season when a new baby steps into the roll as Jesus.   The popular event attracts thousands of people who seek to connect with their religion--and some who do not particularly consider themselves religious, but are interested in learning about the story of Christmas enacted through volunteers.    How do you stay warm? we asked some of the participants of last year's event. Many said the weather isn't really that bad, unless it is drizzling and the wind is blowing. Bundled underneath all the costumes are long-johns, thermal socks, coats and other apparel to ward off the chill in the winter night's air.   None seem to mind the weather, including children who participate and enjoy the sense of community derived from the nativity enactment. From the birth to the three wise men (magi) bringing their Frankincense (used in perfumes and incense), gold and myrrh (another oil-based fragrance, often used for medicinal purposes), the story delivers meaning to participants and community members who each year pile into their cars to drive by and enjoy the beautiful costumes, message and spirit of giving, the impetus for this tradition in Santa Rosa.   For guests visiting, the Living Nativity is normally held mid-December and is free to see.   Santa Rosa Adventist Church Drive-Through Live Nativity at Santa Rosa Adventist Church, 840 Sonoma Ave, Santa Rosa, CA 95404-4715 .  Call the church office at 707-578-8883. santarosasda.org     calsite