Pelagius (354 - 420?) a British monk famous for his piety, but declared a heretic for denying original sin.
After studying Roman law and rhetoric and later theology in England and Rome, he preached in Africa and Palestine, attracting able followers, such as Celestius and Julian of Eclannum. Pelagius thought that Augustine was excessively pessimistic in his view that humanity is sinful by nature and must rely totally upon grace for salvation. Instead Pelagius taught that human beings have a natural capacity to reject evil and seek God, that Christ's admonition, “Be ye perfect,” presupposes this capacity, and that grace is the natural ability given by God to seek and to serve God.^^
Pelagius rejected the doctrine of original sin; he taught that children are born innocent of the sin of Adam. Baptism, accordingly, ceased to be interpreted as a regenerative sacrament. Pelagius challenged the very function of the church, claiming that the law as well as the gospel can lead one to heaven and that pagans had been able to enter heaven by virtue of their moral actions before the coming of Christ. The church fought Pelagianism from the time that Celestius was denied ordination in 411. In 415, Augustine warned Jerome in Palestine that Pelagius was propagating a dangerous heresy there, and Jerome acted to prevent its spread in the East. Pelagianism was condemned by East and West at the Council of Ephesus (431).^ ^
The cause and date of his death are unknown, but two pervading rumours are that he was killed by his enemies in the Roman Church, and the other (perhaps more grounded) that he left Rome in frustration and headed into Africa and died in obscurity.