MONTREAL — When Rabbi Lisa Grushcow, the first openly gay rabbi of a large synagogue in Canada, was preparing to begin rabbinical school, she faced a daunting choice: love or serving God.

Her world was suddenly turned upside down in the late 1990s while she was studying religion at Oxford on a Rhodes scholarship, and fell in love with a woman she met at a conference. This posed a problem: The Conservative rabbinical school she planned to attend did not ordain openly gay rabbis.

Rather than abandoning her vocation, she opted instead to join the Jewish Reform movement — a liberal progressive denomination that accepts gay rabbis and gay marriage. “Coming out,” she added, “brought me closer to God.”

“It was the first time in my life when being good at something and working hard weren’t enough to open the door,” said the bookish 44-year-old rabbi, who speaks with the soothing voice of someone used to softening life’s upheavals. “By following my calling and being true to myself, I was embracing both essential parts of my identity.”