Catholic Adult Formation Course Through CDU. The Diocese of Corpus Christi is partnering with Catholic Distance University (CDU) to provide high-quality online non-credit courses and seminars for general adult formation in any number of topics of interest. Use our diocesan scholarship code: 16CORPUSCHRISTI to receive a discount on all CDU Independent Study Courses. To register and browse our catalog for CDU Independent Study Theology Courses at:  cdu.catalog.instructure.com.