The doctrine of the Trinity is one of the most fundamental doctrines of Christian faith. A number of ancient and even contemporary theologians claim that the doctrine originated in Greek speculative philosophy and that it does not reflect a biblical view of God. There are clear instances of Platonic influence upon the second century Christian writers. Justin's pupil Tatian uses the same analogies to describe the emanation of the Logos and ascribes the role of interaction with the world to the Holy Spirit, probably because he equates the Spirit with the World-Soul. Athenagoras uses the Platonic terms 'Nous' and 'Logos' to describe the Son, and identifies the Logos with the sum of Forms. Both Athenagoras and Clement of Alexandria quote Plato's Letter to demonstrate the necessity of three principles. Therefore, the Christian Trinity or the inner dynamics of the relationship between the Father, Son and Holy Spirit have been formulated using Plato's distinction between the Good, Nous and Pneuma (World Soul). Neo-Platonism, consequently, has a crucial influence on the doctrine of Trinity formulated in the golden age of the church fathers. As we all know, Platonism was not a biblical teaching at all. According to your logic, one must reject "trinity" since it has unbiblical roots. Same way idea of church also has unbiblical roots. The historical reality is that early church-fathers were heavily influenced by various ancient dogmas, cults, and disciplines. Marking any of them as "satanic", knocks the theological tower of Christianity down.
The parallelism btw. Halloween and Trinity is not convincing and logic to me.
1) I simply stated that Halloween is not a feast of the Catholic Church, but celebrated by satanists. And it has not Catholic or Christian routes, but Celtic and pagan ones. The character of Halloween has many in common with okkultism and it can be a true danger for the souls.And it has not Catholic or Christian routes, but Celtic and pagan ones. The character of Halloween has many in common with okkultism and it can be a true danger for the souls.
Some sources:
https://www.jesus.ch/themen/people/erlebt/282015-halloween_war_mein_lieblingsfest.html#:~:text=Nur%20zur%20Info%3A%20Halloween%20ist,wichtigste%20religi%C3%B6se%20Fest%20im%20Jahr.
https://egzorcyzmy.katolik.pl/?s=Halloween
2) Pagan thougths are not always satanic or evil. As I said, in other religions and philosophies can be traces of the truth, but mixed with heresies.
The Quran says that Maria is virgin and that Jesus is called the Messias. But the Quran is not part of the Catholic faith, even though it implies some true statements which we have in common.
3) The Holy Trinity was revealed by Jesus Christ in the Gospel. In the Old Testament are already hints for it. Eventually, there have been similar "ideas" in ancient philosphies like platonism. A true trace in a Greek philosophy. So, if Catholics used those terms which were used by platonists before to explain the doctrine of the Holy Trinity, this does not make it pagan at all.
St. Patrick used a leaf to illustrate th trinity...but this does not make the Holy Trinity a plant or biological object.
4) Satanism and paganism is not always the same.