During the period of the Roman Empire when Christians were persecuted, many saved their lives by renouncing their Christian faith. Some said these people were guilty of the religious crime of apostasy.
Baptism and Apostasy:
A controversy arose as a result of the apostasy that occurred following Emperors Galerius and Diocletian's persecution of Christians beginning in 303. Could a priest guilty of apostasy confer baptism/absolution? St. Augustine and others later ruled that he could since a baptism is not really conferred by the priest but by Christ. At the time, the Church -- but not with the agreement of all its members -- ruled that with penance and atonement, lapsed Christians could fully rejoin the community.
In A.D. 311, some Christians were upset when an apostatic archdeacon was ordained Bishop of Carthage, so they set up their own Bishop of Carthage: Majorinus in A.D. 311 and Donatus in A.D. 315. It was after this Bishop Donatus that the Donatist schism was named.
Donatists would not accept baptisms performed by people who were not members of their sect. Those who joined the Donatists had to perform penances and be re-baptized. The Council of Arles in A.D. 314 condemned the Donatists, but they flourished, anyway. The two communities in Africa -- Donatists and Orthodox Catholics -- were at each other's throats. In A.D. 393 St. Augustine codified Catholic teaching about baptism based on the controversy between Donatists and Orthodox Catholics. Since his teaching and diplomatic efforts did not stop the bickering and fighting, the powers of government were invoked. In A.D. 411, an imperial commission condemned Donatism and made its practice illegal.