On October 27, 2018, after a domestic terrorist murdered 11 worshipers in a mass shooting at Tree of Life Synagogue, Rabbi Creditor spoke alongside Mayor Bill de Blasio, Cardinal Timonthy M. Dolan, and other New York faith and elected leaders. Two months later, he published "Holding Fast: Jews Respond to American Gun Violence," a collection of teens, rabbis, and others from the Tree of Life community and beyond, calling as Jews for an end to American Gun Violence.