Satanism in the Roman Catholic Church

Religious policy

Further information:
Constantine I and Christianity and Constantine I and Judaism
Constantine the Great, mosaic in Hagia Sophia, c. 1000
Constantine is perhaps best known for being the first Christian Roman emperor; his reign was certainly a turning point for the Christian Church.
In 313 Constantine announced toleration of Christianity in the Edict of Milan, which removed penalties for professing Christianity
(under which many had been martyred in previous persecutions of Christians)
and returned confiscated Church property. Though a similar edict had been issued in 311 by Galerius, then senior emperor of the Tetrarchy, Galerius' edict granted Christians the right to practice their religion but did not restore any property to them.
Scholars debate whether Constantine adopted his mother St. Helena's Christianity in his youth, or whether he adopted it gradually over the course of his life.
Constantine would retain the title of pontifex maximus until his death, a title emperors bore as heads of the pagan priesthood, as would his Christian successors on to Gratian (r. 375–83).
According to Christian writers, Constantine was over 40 when he finally declared himself a Christian, writing to Christians to make clear that he believed he owed his successes to the protection of the Christian High God alone.
Throughout his rule, Constantine supported the Church financially, built basilicas, granted privileges to clergy
(e.g. exemption from certain taxes),
promoted Christians to high office, and returned property confiscated during the Diocletianic persecution.
His most famous building projects include the Church of the Holy Sepulchre, and Old Saint Peter's Basilica.
Constantine did not patronize Christianity alone, however. After gaining victory in the Battle of the Milvian Bridge, a triumphal arch—the Arch of Constantine—was built to celebrate;
the arch is decorated with images of Victoria and sacrifices to gods like Apollo, Diana, or Hercules, but contains no Christian symbolism.
In 321, Constantine instructed that Christians and non-Christians should be united in observing the
"venerable day of the sun",
referencing the esoteric eastern sun-worship which Aurelian had helped introduce, and his coinage still carried the symbols of the sun-cult until 324.
Even after the pagan gods had disappeared from the coinage, Christian symbols appear only as Constantine's personal attributes: the chi rho between his hands or on his labarum, but never on the coin itself.
Even when Constantine dedicated the new capital of Constantinople, which became the seat of Byzantine Christianity for a millennium, he did so wearing the Apollonian sun-rayed Diadem.
Constantine burning Arian books
The reign of Constantine established a precedent for the position of the emperor in the Christian Church. Constantine himself disliked the risks to societal stability, that religious disputes and controversies brought with them, preferring where possible to establish an orthodoxy.
The emperor saw it as his duty to ensure that God was properly worshipped in his empire, and what proper worship consisted of was for the Church to determine.
In 316, Constantine acted as a judge in a North African dispute concerning the validity of Donatism.
After deciding against the Donatists, Constantine led an army of Christians against the Donatist Christians.
After 300 years of pacifism, this was the first intra-Christian persecution. More significantly, in 325 he summoned the Council of Nicaea, effectively the first Ecumenical Council
(unless the Council of Jerusalem is so classified),
Nicaea was to deal mostly with the heresy of Arianism. Constantine also enforced the prohibition of the First Council of Nicaea against celebrating the Lord's Supper on the day before the Jewish Passover (14 Nisan)
( Quartodecimanism and Easter controversy).
Constantine made new laws regarding the Jews.
They were forbidden to own Christian slaves or to circumcise their slaves.