[Mark17]

Paganism

Yes, I agree, purgatory is paganism, but what motivated them to introduce paganism?

[aMorePerfectUnion]

Mark, it is first, the history of mankind to turn from the true God to idols.

Just look at the OT.

Instead of God, many turned to a golden calf.

Instead of God, many worshipped a bronze snake.

Instead of God as ruler of a nation, they wanted a man, so they could be like the other nations.

Paganism never loses is pull

Just look at the worship of idols of fertility Rome is featuring currently.

20 years from now, they will join “sacred tradition” with the other pagan practices.

[Antoninus]

Yes, I agree, purgatory is paganism, but what motivated them to introduce paganism?

Recall that the "reformers" saw paganism under every rock. In doing so, they had to trash practically every ancient Father and Mother of the early Church. This explains why protestants do their utmost not to read the works of the early Church. Sadly, without doing so, your understanding of Sacred Scripture will, of necessity, be deeply flawed.