At the time of Constantine it was. Constantine himself, not so much.
The Romanization of Christianity was after Constantine. The issue was Rome making Christianity the religion of the Roman Empire.
Right, so now Christianity wasn’t paganised under Constantine as many have been telling me for years. It was some time later, now.
Presumably people have read some of Constantine’s writings and edicts, and seen how untenable that idea ever was.
Constantine removed pagans from sacred sites like Abraham’s Altar, and issued the death penalty for any pagan who tried making sacrifices there. He ordered a Church be on the site to protect it.
Constantine’s mother-in-law was horrified seeing pagan sacrifices and rituals there and informed him of it.
This is what happened when Rome mandated Christianity. Pagan worship continued under the guise of the Christian faith.
The Eucharist became the focal point of worship (as it was with the Roman mystery religions). Rituals and Sacraments were implemented. The priesthood was reinstalled. Biblical churches could not legally exist.
The Eucharist was the Christian focal point long before Constantine or the supposed pagan corruption timeline you suggest after him.
“But what consistency is there in those who hold that the bread over which thanks have been given is the Body of their Lord, and the cup His Blood, if they do not acknowledge that He is the Son of the Creator of the world…” Irenaeus, Against Heresies, IV:18, 2 (c. A.D. 200).
“For the blood of the grape–that is, the Word–desired to be mixed with water, as His blood is mingled with salvation. And the blood of the Lord is twofold. For there is the blood of His flesh, by which we are redeemed from corruption; and the spiritual, that by which we are anointed. And to drink the blood of Jesus, is to become partaker of the Lord’s immortality; the Spirit being the energetic principle of the Word, as blood is of flesh. Accordingly, as wine is blended with water, so is the Spirit with man. And the one, the mixture of wine and water, nourishes to faith; while the other, the Spirit, conducts to immortality. And the mixture of both–of the water and of the Word–is called Eucharist, renowned and glorious grace; and they who by faith partake of it are sanctified both in body and soul.” Clement of Alexandria, The Instructor, 2 (ante A.D. 202).
“For not as common bread and common drink do we receive these; but in like manner as Jesus Christ our Saviour, having been made flesh and blood for our salvation, so likewise have we been taught that the food which is blessed by the prayer of His word, and from which our blood and flesh by transmutation are nourished, is the flesh and blood of that Jesus who was made flesh.” Justin Martyr, First Apology, 66 (A.D. 110-165).
“He acknowledged the cup (which is a part of the creation) as his own blood, from which he bedews our blood; and the bread (also a part of creation) he affirmed to be his own body, from which he gives increase to our bodies.” Irenaeus, Against Heresies, V:2,2 (c. A.D. 200).
“Then, having taken the bread and given it to His disciples, He made it His own body, by saying, ‘This is my body,’ that is, the figure of my body. A figure, however, there could not have been, unless there were first a veritable body. An empty thing, or phantom, is incapable of a figure. If, however, (as Marcion might say,) He pretended the bread was His body, because He lacked the truth of bodily substance, it follows that He must have given bread for us. It would contribute very well to the support of Marcion’s theory of a phantom body, that bread should have been crucified! But why call His body bread, and not rather (some other edible thing, say) a melon, which Marcion must have had in lieu of a heart! He did not understand how ancient was this figure of the body of Christ, who said Himself by Jeremiah: ‘I was like a lamb or an ox that is brought to the slaughter, and I knew not that they devised a device against me, saying, Let us cast the tree upon His bread,’ which means, of course, the cross upon His body. And thus, casting light, as He always did, upon the ancient prophecies, He declared plainly enough what He meant by the bread, when He called the bread His own body.” Tertullian, Against Marcion, 40 (A.D.
Christians could no longer gather in congregations under an "overseer" chosen from that congregation but were forced to accept the pagan priesthood of Rome or face persecution.
Christian congregations electing their own overseerers/ Bishops is unbiblical, they were always Apostolically appointed through the laying on of hands by those that were approved and appointed.
The Catholic Church is just as much pagan as it is Christian (probably more pagan than Christian). That does not mean the gospel isn't there. Reformed Churches are just as much Catholic as they are Christian as well.
You haven’t proven pagan practices in the Catholic Church, the Church under persecution celebrated the Eucharist long before Constantine and view it as Catholics view it today, as the Body and Blood of Jesus, to be eaten and to drink unto Salvation.
Jesus established The Eucharist and Priesthood with the Apostles, not pagans.