When men err in ignorance, following closely their own notions of right and wrong, though these notions are mistaken,—great as is their sin, if they might have possessed themselves of truer notions (and very great as was St. Paul's sin, because he certainly might have learned from the Old Testament far clearer and diviner doctrine than the tradition of the Pharisees),—yet such men are not left by the God of all grace. God leads them on to the light in spite of their errors in faith, if they continue strictly to obey what they believe to be His will.
--Blessed John Henry Newman, "St. Paul's Conversion Viewed in reference to His Office", Parochial and Plain Sermons, Vol. 2
