Mater Dei Parish of Sioux City will hold a Joyful Catholics gathering at 6 p.m. on Jan. 16. The event will feature Mary Stevens and Betty Pratt who will speak about Catholic ministries committed to growing vocations. Stevens will address the Seven Sisters Apostolate & 31 Club. Pratt will speak about the St. Serra Club of Siouxland. The gathering will be held in the Nativity Center.