WASHINGTON — Rabbi Charlie Cytron-Walker of Congregation Beth Israel in Colleyville, Texas, testified before members of Congress Tuesday about his harrowing experience during a hostage standoff last month. “I welcomed a terrorist into my congregation,” Cytron-Walker said. “I live with that responsibility.” Cytron-Walker told lawmakers he let the stranger into the synagogue and served him tea one Saturday morning last month. “I spent time to see if there were any red flags,” Cytron-Walker said. “I didn’t see any. Of course, I was wrong.” That man ended up taking the rabbi and three others hostage at gunpoint. Cytron-Walker said security training...