The Roman Empire was under threat by the division of the empire, internal and religious discord, outward pressure of the barbarians (people who did not belong to the great civilisations; Greek, Roman, Christian). The great Spirit/power of Rome was fast departing. Christianity seemed like the only efficient power for a political reformation of the Empire.
Idolatry also had outlived itself in the Roman Empire, Christianity could breathe new life into it, as the Christians were following already pagan traditions instituted by Saint Paul.
Prior to this, Christians were persecuted under the Roman Empire for centuries. Constantine stopped the persecution of the Christians and improved the condition of slaves. Even though he was promoting Christianity, he himself wasn’t practising it.
Historian J L Mosheim states "The Christian bishops introduced, with but slight alterations, into the Christian worship, those rites and institutions by which formerly the Greeks and Romans and others had manifested their piety and reverence toward their imaginary deities; supposing that the people would more readily embrace Christianity if they perceived the rites handed down to them from their fathers still existing unchanged among the Christians, and saw that Christ and the martyrs were worshipped in the same manner as formerly their gods were.”
The Catholic Encyclopaedia states that believers are “to worship God and then to pray, first to Saint Mary, and the holy apostles, and the holy martyrs, and all God's saints, that they would intercede for them to God. In this way they learned to look up to the saints in heaven with feelings of confidence and affection, to consider them as friends and protectors, and to implore their aid in the hour of distress, with the hope that God would grant to the patron what he might otherwise refuse to the supplicant.”
This is not biblical at all and was not taught by any of the prophets. This is an invention of the Catholic Church. These saints are avatars of pagan gods.
Pagan statues (of gods) were re-labelled. Isis and Horus became Mary and Jesus. Statues of Jupiter were re-labelled to Saint Peter. Just like the one in the Vatican where millions of visitors touch and kiss its feet.
You can tell it is a sun god by the sun disk behind its head.
Romulus and Remus re-labelled to the great martyrs Cosmas and Damian. Hermes becomes Christ the good shepherd.
God is the Father alone; He is worshipped by all the prophets—peace be upon them—including the Prophet Jesus, peace be upon him.
Christ said
3 Now this is eternal life: that they know you, the only true God, and Jesus Christ, whom you have sent.
John 17:3
Christ also did not claim divinity and restricted divinity to God (the Father) alone
He did not say that he is a god or that the Holy Spirit is a god
جاء لمناظرة الشيخ عثمان… ثم نطق الشهادة وأسلم!
‼
https://www.youtube.com/watch?v=jkDvqDKR4j0
«إثبات ألوهية يسوع لمسلم؟!» "لا تستخدم العقل في الدين!"… هاشم يواجه مسيحيًا في مناظرة مشتعلة!
‼
https://www.youtube.com/watch?v=DlvZ31tXDN0
Was Jesus the Founder of Christianity? How the Religion of Jesus was Corrupted
https://www.youtube.com/watch?v=0I_xUl1boVM
سيدة في مواجهة اثنين تقع في "صدمة الفلسفة بالتحليل" حوار عاصف حول غموض الإنجيل أمام حمزة ومنصور‼
https://www.youtube.com/watch?v=v7T4_p2aWXI
عضو الكنيسة الأرثوذكسية الإثيوبية يتحدى الشيخ عثمان حول ألوهية المسيح والتثليث! النتيجة صادمة 
‼