From Homilies on First CorinthiansHomily 2  

 “God is faithful, by whom you were called unto the fellowship of His Son.” Wonderful! How great a thing says Paul here! How vast in the magnitude of the gift which he declares! Into the fellowship of the only-begotten have you been called, and do you addict yourselves unto men? What can be worse than this wretchedness? And how have you been called? By the Father. For since “through Him,” and “in Him,” were phrases which Paul was constantly employing in regard of the Son, lest men might suppose that he so mentions Him as being less, he ascribes the same to the Father. For not by this one and that one, says he, but by the Father have you been called; by Him also have you been enriched. Again, you have been called; ye did not yourselves approach… 

… It is God who calls, and calls by Himself.  What pardon can they deserve, who do not come running to Him? Let no one therefore accuse God; for unbelief comes not of Him who calls, but of those who start away from Him…. 

…Why do we, for the most part, deceive ourselves in vain with heartless pretexts and excuses, gaining not only no pardon, but instead intolerable punishment? When we ought to keep before our eyes that fearful day, and to give heed to virtue; and after a little labor, obtain the incorruptible crowns? For these words will be no defense to us.”

Saint John Chrysostom (ca. 347-407) was Archbishop of Constantinople, and one of the greatest preachers of his era. He is traditionally counted among the Four Great Doctors of the Eastern Church.  The Homilies on I Corinthians date from his ministry in his native Antioch, and were preached in the 380s and 390s. His feast day is September 13.