Why does early Christians plagiarized the dogma of Hell from pagan philosophers Plato and Virgil?

In the words of the Athanasian Creed :

"the Father is God, the Son is God, and the Holy Spirit is God, and yet there are not three Gods but one God."

In this Trinity of Persons the Son is begotten of the Father by an eternal generation, and the Holy Spirit proceeds by an eternal procession from the Father and the Son. Yet, notwithstanding this difference as to origin, the Persons are co-eternal and co-equal: all alike are uncreated and omnipotent.

In Scripture there is as yet no single term by which the Three Divine Persons are denoted together. The word trias (of which the Latin trinitas is a translation) is first found in Theophilus of Antioch about A.D. 180. He speaks of "the Trinity of God [the Father], His Word and His Wisdom . The term may, of course, have been in use before his time. Afterwards it appears in its Latin form of trinitas in Tertullian In the next century the word is in general use. It is found in many passages of Origen . The first creed in which it appears is that of Origen's pupil, Gregory Thaumaturgus.

St. John's testimony is yet more explicit than that of the Synoptists. He expressly asserts that the very purpose of his Gospel is to establish the Divinity of Jesus Christ ( John 20:31 ). In the prologue he identifies Him with the Word, the only-begotten of the Father, Who from all eternity exists with God, Who is God ( John 1:1-18 ).

In 2 Corinthians 13:13 , St. Paul writes: "The grace of our Lord Jesus Christ, and the charity of God, and the communication of the Holy Ghost be with you all." Here the construction shows that the Apostle is speaking of three distinct Persons. Moreover, since the names God and Holy Ghost are alike Divine names, it follows that Jesus Christ is also regarded as a Divine Person. So also, in 1 Corinthians 12:4-11 : "There are diversities of graces, but the same Spirit ; and there are diversities of ministries, but the same Lord: and there are diversities of operations, but the same God, who worketh all [of them] in all [ persons ]." (Cf. also Ephesians 4:4-6 ; 1 Peter 1:2-3 ).

To sum up: the various elements of the Trinitarian doctrine are all expressly taught in the New Testament. The Divinity of the Three Persons is asserted or implied in passages too numerous to count. The unity of essence is not merely postulated by the strict monotheism of men nurtured in the religion of Israel, to whom "subordinate deities" would have been unthinkable; but it is, as we have seen, involved in the baptismal commission of Matthew 28:19 , and, in regard to the Father and the Son, expressly asserted in John 10:38 . That the Persons are co-eternal and coequal is a mere corollary from this. In regard to the Divine processions, the doctrine of the first procession is contained in the very terms Father and Son : the procession of the Holy Spirit from the Father and Son is taught in the discourse of the Lord reported by St. John ( 14-17 )

Oh? And here I was under the impression the concept of heaven was taken from Zeus' s abode above the clouds on mount Olympus and hell was taken from the Roman concept of Hades, or Pluto's dark world where the character they based Jesus partially on, Adonis, lived for half the year during which time all the leaves fell from the trees and the world was all cold and ugly. Then he dwelled in Hades, where he cuckolded Pluto in Hades by cheating with his wife, Persephone until the time he comes back to visit the earth to be with his other lover, Aphrodite (VENUS) during the spring solstice. Upon the return of Zeus's half god half mortal son, Adonis, with his long hair and crown of branches, dressed in a loincloth, is greeted by the spring goddess Ishtar (Easter) whose fertility was celebrated with brightly colored eggs and rabbits.

Holy holy holy is the Lord of hosts is a reoccurring theme in the Holy Scriptures of Moses, and three is a number representing infinity and the three sides of the isosceles triangle, which, when doubled, is the star of David which was taken from Hinduism, the mother of Judaism.

And isn't Christos based on Lord Christna /Krishna with his halo and never touching any but one woman, Rhadi? And Catholic rosary beads are copies from Hindu mantra beads called Japa beads used to count prayers while repeating words until they become nonsensical and holding each bead til the prayer is done so as to keep the mind on recitation instead of counting?

Everyone copies, it seems, from Hindus. And from Jews. An Inam in Kasmir once told me that the caps the Muslims wear is a copy of Jewish Yalmulkes. Now, I always thought Yalmulkes were worn by old balding men to keep that bald spot on top from getting sunburned in the desert, and they only make them small because there wasn't enough trees to supply material to weave a nice big hat that would provide shade, so they used a cloth wrapped about their head ?

Even America copied the American indians when the democratic government was designed. And, the electoral college was copied after Rome's remembered first true democracy when the writers of the Declaration of the Indsependance renegged on their claim that all men were created equal with equal rights in the eyes of the law... and, to keep poor people from making major uneducated decisions that didn't serve the wealthy in the new American democracy, they inserted the electoral college

The founding fathers were afraid of direct election to the Presidency. They feared a tyrant could manipulate public opinion and come to power. Hamilton wrote in the Federalist Papers:

It was equally desirable, that the immediate election should be made by men most capable of analyzing the qualities adapted to the station, and acting under circumstances favorable to deliberation, and to a judicious combination of all the reasons and inducements which were proper to govern their choice. A small number of persons, selected by their fellow-citizens from the general mass, was supposed to possess the information and discernment to safeguard this.

Then Obama came along.

Emperor Constantine put a whole lot of Christian things with pagan festivals and the like in order to stop the pagans getting outrageously angry when they were switched to Christianity. For example, Christmas corresponds with the Saturnalia festival (it's not actually Jesus' birthday).

Therefore it makes sense why there would be parallels between Christianity and pagan beliefs.

They recycled old myths heavily, because they were effective.