Marcionite Influence on the Roman Catholic Church
From Anti-Docetic in 207 AD To Pro-Docetic By 368 AD
Apostle John made it clear that the most dangerous doctrine in Christianity is to believe Jesus did not come in true human flesh, but only appeared to have human flesh. This heresy is known as Docetism -- from the Greek word for 'appear.'
Apostle John says docetism is the message of the Anti-Christ (i.e., Satan). Apostle John said: "Many deceivers, who do not acknowledge Jesus Christ as coming in human flesh [Greek, sarx, human flesh], have gone out into the world. Any such person is the deceiver and the antichrist." (2 John 1:7.)
Marcion in 144 AD argued Jesus was God, and as such could not be wrapped in true human flesh because it is inherently sinful. As a result, Jesus supposedly did not suffer any pain on the cross.
However, when Marcionism became powerful, by 207 A.D. the early church through Tertullian's pen battled such ideas of Marcion. Tertullian, a major church leader in North Africa, battled vigorously against this claim, insisting that "Christ really became a man." (Tertullian, The Flesh of Christ at this link.)
As to Marcion's claim that Jesus as God could not have suffered in the flesh because His flesh was a mere phantom, Tertullian responded with alarm: "Have you, then, cut away all sufferings from Christ, on the ground that, as a mere phantom, He was incapable of experiencing them?" (Tertullian, The Flesh of Christ, ch. 5.) And most clearly mocked Marcion by saying:
O thou most infamous of men, who acquittest of all guilt the murderers of God! For nothing did Christ suffer from them, if He really suffered nothing at all. Id., Ch. 5.
Tertullian said this is why Jesus is called the Son of Man -- to tell us Jesus was indeed a true man: "Else why is Christ man and the Son of man, if he has nothing of man, and nothing from man?" (Tertullian, id, at Ch. 5.)
However, in the late 300s, the Roman Catholic Church lost hold on this original orthodox view. It got confused by Paul and apparently by Marcion. The Roman Catholic Church now thought Jesus only appeared to be a man. It denied Jesus had human flesh and thus denied Jesus could actually suffer pain.
First, St. Hilary of Poitiers (300-368) in On The Trinity said "No more in the passion did the flesh of Christ feel pain than if you were to wound fire or water with a sword." (Hilary, De Trinitate Bk. 9: 56 and Bk. 10:23. See Nicene Fathers by Schaff ...Hillary at page 195 under hits at this link.)
Second, Jerome from the 400s commented on Matthew 26 that it was ridiculous to think Jesus "was afraid of death" or "spoke in terror about the passion" (Jerome, In Matthaeum Bk. IV ch. 26:39.)
Finally, Aquinas in the 1200s persisted with this notion that Jesus's flesh was not truly human: "It would seem that there was no true sensible pain in Christ." (Summa Theologia (2007) Vol. IV at 2102.) Aquinas argued from Hillary and the Virgin Birth that Jesus's flesh was "under no necessity of suffering pain." Id.
Jerome, Hillary and Aquinas were infected by the message of what John said came from the Anti-Christ (i.e., Satan). These otherwise brilliant scholars did not agree Jesus came in "human flesh." They thought His body only appeared to have human flesh, but was somehow a spiritually divine flesh that was impervious to pain or fear.
Marcionite View That Law Of Moses Entirely Defunct Ingested by RCC
Marcion's doctrine insisted on the defunct nature of the Law given Moses.
The earlier voices in orthodox Christianity favored the Law/Decalogue as still binding with only the ceremonial law not continuing. (See Early Church View of the Law.)
However, the Roman Catholic Church accepted by 363 AD the abolition of Sabbath on Saturday (see our link); it also moved Passover celebration to Easter -- the time of worship of the goddess Easter / Osiris; and it came to accept Paul's notion of the abrogation of the Mosaic Law's commands, etc. (See our link on Easter.)
Marcionite View Jesus Had No Siblings (And Mary Was Perpetual Virgin)
In 207 AD, Tertullian criticized Marcion for deleting from the Gospel account (similar to Luke's version) that Jesus had any siblings. Marcion did so evidently to support the doctrine Jesus was not a true man, and his flesh was spiritually unique. To that end Marcion deleted Jesus had any siblings, apparently matching a view that Mary after a virgin birth of Jesus then had no other children. This is identical to later Catholic teaching. See our webpage discussing this Marcionite tampering with the gospels.
There were other contemporaries of Marcion who promoted similar views. For example, Valentinus. Plausibly he was a follower of Marcion. For more on Valentinus, see our article "Valentinus."
Docetism appears in many trinitarian explanations of Holy Scripture. So if Jesus is said to be hungry, and the devil comes to tempt him, the trinitarian says this is Jesus pretending to be hungry. In Macarius Magnes Apocritus ch. X (likely written between 300 and 400 AD) we read: "it was only when He pretended to be hungry that the devil attacked him as he had the first Adam and beat him." See link.