Lives of the Saints, by Alban Butler, Benziger Bros. ed. [1894], at sacred-texts.com
ST. CELESTINE was a native of Rome, and upon the demise of Pope Boniface he was chosen to succeed him, in September 422, by the wonderful consent of the whole city. His first official act was to confirm the condemnation of an African bishop who had been convicted of grave crimes. He wrote also to the bishops of the provinces of Vienne and Narbonne in Gaul, to correct several abuses, and ordered, among other things, that absolution or reconciliation should never be refused to any dying sinner who sincerely asked it; for repentance depends not so much on time as on the heart. He assembled a synod at Rome in 430, in which the writings of Nestorius were examined, and his blasphemies in maintaining in Christ a divine and a human person were condemned. The Pope pronounced sentence of excommunication against Nestorius, and deposed him. Being informed that Agricola, the son of a British bishop called Saverianus, who had been married before he was raised to the priesthood, had spread the seeds of the Pelagian heresy in Britain, St. Celestine sent thither St. Germanus of Auxerre, whose zeal and conduct happily prevented the threatening danger. He also sent St. Palladius, a Roman, to preach the Faith to the Scots, both in North Britain and in Ireland, and many authors of the life of St. Patrick say that apostle likewise received his commission to preach to the Irish from St. Celestine, in 431.
[paragraph continues] This holy Pope died on the 1st of August, in 432, having reigned almost ten years.
Reflection.—Vigilance is truly needful to those to whom the care of souls has been confided. "Blessed are the servants whom the Lord at His coming shall find watching."