Complex sentence: The voluntary aspect is the efforts of the infallible to act according to God's orders; the involuntary one includes the training and the inheritance which the person has no role in acquiring them but a special favour from God for the infallible.
Split into simpler sentences: The voluntary aspect focuses on the efforts of the infallible to act accordingly to God's orders. The involuntary one includes the inheritance and training of one who has no role in acquiring them but is deemed to be a special favour from God for the infallible.