Bishop Gerasim was born in 1961, in Torrance, California, and raised in Palos Verdes. Growing up, he initially attended the Episcopal Church, and later the Presbyterian. As a child he had a diverse range of interests: sports, history, science fiction, and stamp-collecting, which offered a window to foreign lands and languages. He graduated from University High School in Irvine in 1979, simultaneously taking classes at UC Irvine during his senior year.