Christianity Prevails: From Persecution to Official State Religion

Timeline and Resilience: Christianity underwent approximately $2.5$ centuries of persecution from the Roman Empire.
Survival: Despite these efforts, the group — often described as "seditious" by Roman authorities — outlasted the most severe periods of state-sanctioned violence.
The Diocletian Era ( $285-305\,CE$ ): This period marked the most intense and final major persecution launched against the Christian population before the religion's eventual triumph.
Correlation with Imperial Health: The level of persecution was historically tied to the stability and "declining fortunes" of the Roman Empire itself. * Nero and Domitian: Persecutions under these emperors occurred during times of internal strife focused specifically on the person and character of the emperor. * The "Five Good Emperors": While persecution continued during this period, it only became particularly localized and pointed during the reign of Marcus Aurelius. * Stability Indicators: Under Marcus Aurelius, the empire faced significant problems, including pestilence within Rome and the appearance of barbarians on the frontiers. * The Successor Factor: Political instability began to increase rapidly starting with Commodus, who was the son of Marcus Aurelius.

Third Century Instability: By the time the Empire entered its $3rd$ century, it reached a state of extreme instability.
Religious Proliferation: Because of this lack of stability, a variety of new religions and superstitious practices cropped up alongside Christianity, including: * Mithras (a mystery religion). * Isis (a mystery religion). * Neo-Platonism.
Diocletian’s Restoration of Order: To manage the sprawling and fractured empire, Diocletian established the Tetrarchy, which translates to "rule by four."
Diocletian’s Persecutions: Despite restoring political stability, Diocletian mounted the most severe persecution Christians had ever faced. * Methods of Oppression: This era saw peak levels of legal prosecutions, executions, and the confiscation of private properties and church estates. * Motivation: These expanded efforts to eradicate Christianity occurred when the empire was at its most destabilized point politically, economically, and socially. The move was driven by complex systemic issues rather than exclusively by religious differences.

The Power Vacuum: After Diocletian retired from the Tetrarchy, a civil war erupted among his successors as various leaders vied for total control.
The Vision of Constantine: During this conflict, Constantine emerged as the primary victor over his most serious rival, Maxentius. * The Celestial Sign: Constantine experienced a vision of a sign in the sky accompanied by the phrase "In hoc signo, vinces" (In this sign, you will conquer). * Symbolism: The vision included the entwined Greek letters Chi ( $X$ ) and Rho ( $P$ ), representing the first two letters of Christ.
The Battle at the Milvian Bridge: On the day following the vision, Constantine’s victory at this battle sealed his ascendancy to power.
The Edict of Milan: Constantine fundamentally reversed Roman policy regarding Christianity. While the Edict officially made Christianity a "tolerated" religion, in practice, it became the "favored" religion of the state.
Key Policy Changes under Constantine: * Restoration: He oversaw the return of properties to individuals and churches that the state had previously confiscated. * Legal Reform: He granted Christians the opportunity to appeal standard legal judgments to Christian bishops. * Military Accommodations: Christian soldiers were officially allowed to have Sundays off from their duties.

Purpose of the Council: Constantine convened a major church council at Nicaea in $325\,CE$ to settle theological disputes that threatened the unity of the empire.
Theological Focus: The council addressed the specific nature of Christ Himself.
The Arian Controversy: Arianism was the most significant alternative view at the time. The disagreement between Arian and non-Arian adherents led to significant social disruption and physical violence between opposing groups.
Constantine’s Objective: It is suggested that Constantine was less interested in the specific theological outcome of the council and more concerned with ending the controversy and the disruptions it caused.
The Nicene Creed: The council produced a formal theological statement known as the Nicene Creed, which defined the orthodox view for mainline Christianity from that point forward.
Constantine’s Personal Faith: History questions to what extent Constantine personally conformed to the Nicene Creed; however, he did submit to Christian baptism while on his deathbed.

From Toleration to Official Status: Within a few generations of Constantine's reign, the Roman Emperor Theodosius declared Christianity the official religion of the Roman Empire.
Shift of Authority: When the last of the Roman emperors stopped ruling in the Western half of the empire, authority increasingly fell into the hands of the Roman Church.