It’s Friday evening. A group of young people gather in the living room of a spacious home in Silver Spring, Maryland, light Sabbath candles and sing hymns in Hebrew. Three are still busy in the kitchen, preparing the Sabbath-eve meal, featuring baked fish, guacamole and watermelon slices. After the ritual hand-washing, wine glasses are passed around. Some of the 17 people there don skullcaps for the blessing, which ends with an impressive “Amen.”

But all of this is not necessarily about religion.