"He that discerneth these things, every fellow-believer, let him pray for Abercius"
Carved right in stone, the evidence of prayers for the dead. Christians who were buried in the first centuries asked the people reading their gravestones to pray for them.
Why? Why would they do that?
“who died in Phrygia ca. A.D. 167:
‘”He that discerneth these things, every fellow-believer, let him pray for Abercius”
“Carved right in stone, the evidence of prayers for the dead.
..............
Here’s an even earlier reference to heresy...
Revelation 2-3:22
Churches practicing heresy. This before the heresy you note, so it is not surprising that there was heresy afterwards also. In fact, I do not believe the Church has ever been free of heresy from within or without.
Indeed, like why would such also pray to created beings in Heaven when there is no one single record of anyone but pagans doing so in the entire God-inspired record of Scripture - despite there being over 200(!) prayers therein , or any teaching to pray to them?
By 90AD we know false beliefs were gaining disciples, and the history of Catholicism continues that record.
And praying for the dead was a latter development among some Jews, flowing from paganism.
...it should come as no surprise that we do find instances, particularly in the domain of popular belief, in which non-Christians prayed for the suffering dead in the other world.. .
These practices developed around the beginning of the Christian era. They were a phenomenon of the times, particularly noticeable in Egypt, the great meeting ground for peoples and religions. Traveling in Egypt around 50 s.c., Diodorus of Sicily was struck by the funerary customs: "As soon as the casket containing the corpse is placed on the bark, the survivors call upon the infernal gods and beseech them to admit the soul to the place received for pious men. The crowd adds its own cheers, together with pleas that the deceased be allowed to enjoy eternal life in Hades, in the society of the good.
The passage cited earlier from the Second Book of Maccabees, which was composed by an Alexandrian Jew during the half-century preceding Diodorus's journey, should no doubt be seen against this background... It then becomes clear that at the time of Judas Maccabeus--around 170 s.c., a surprisingly innovative period—prayer for the dead was not practiced, but that a century later it was practiced by certain Jews. (The Birth of Purgatory By Jacques Le Goff. pp. 45,46 , transcribed using Free Online OCR - convert scanned PDF and images to Word, JPEG to Word, emp. mine)
Uh; because they had no assurance of salvation??