Pope St. Cornelius whose feast day is September 16th. A Roman priest, Cornelius was elected Pope to succeed Fabian in an election delayed fourteen months by Decius’ persecution of the Christians. The main issue of his pontificate was the treatment to be accorded Christians who had been apostasized during the persecution.
He condemned those confessors who were lax in not demanding penance of these Christians and supported St. Cyprian, Bishop of Carthage, against Novatus and his dupe, Felicissimus, whom he had set up as an antibishop to Cyprian, when Novatus came to Rome. On the other hand, he also denounced the Rigorists, headed by Novatian, a Roman priest, who declared that the Church could not pardon the lapsi (the lapsed Christians), and declared himself Pope – the first antipope.
The two extremes eventually joined forces, and the Novatian movement had quite a vogue in the East. Meanwhile, Cornelius proclaimed that the Church had the authority and the power to forgive repentant lapsi and could readmit them to the sacraments and the Church after they had performed proper penances. A synod of Western bishops in Rome in October 251 upheld Cornelius, condemned the teachings of Novatian, and excommunicated him and his followers. When persecutions of the Christians started up again in 253 under Emperor Gallus, Cornelius was exiled to Centum Cellae (Civita Vecchia), where he died a martyr probably of hardships he was forced to endure.
Source : usatholic