The claim that the Trinity is of pagan origin is ridiculous. First, this question of origin is a non-issue when the inspired, infallible text of Scripture is clear that:
The Father is God
“Labour not for the meat which perisheth, but for that meat which endureth unto everlasting life, which the Son of man shall give unto you: for him hath sealed.” (John 6:27)
The Son is God
“And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory.” (1 Timothy 3:16)
The Holy Ghost is God
“But Peter said, Ananias, why hath Satan filled thine heart to lie to the Holy Ghost, and to keep back part of the price of the land? Whiles it remained, was it not thine own? and after it was sold, was it not in thine own power? why hast thou conceived this thing in thine heart? thou hast not lied unto men, but unto God.” (Acts 5:3-4)
There is only one, true God
“Seeing it is one God, which shall justify the circumcision by faith, and uncircumcision through faith.” (Romans 3:30)
God is eternally in three persons
“For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one. (1 John 5:7-8).
Satan Counterfeits The Real Thing
Second, it is no less true that Satan (who has SEEN God–Job 1:6 & Isaiah 14:12-14) is fully aware of the Triune nature of God. Therefore, it is expected that he would counterfeit the trinity–which explains the different pagan traditions. Satan has produced false bibles, false religions, false spirits and will soon unveil a false Christ for the end times.
(You should also note that NONE of Satan’s counterfeits are the same as Biblical Christianity’s Trinity. They are actually a representation of Tri-theism, which is pantheism–three gods or three headed gods.)
Our Awesome God: Beyond Description or Comprehension
The Trinity is difficult to explain because it is an attempt to explain the nature and essence of the Almighty God. If I were to say that this Universe is beyond our understanding, I am speaking a truth. Then how much beyond our understanding is the Creator God who made that Universe that itself is beyond our comprehension?
Any definition of God that is simple and understandable is obviously a man-made fiction. And every definition of God, outside of Biblical Christianity, is small and simple–an obvious scam.
Here is an article that just scratches the surface, but is filled with undeniable facts about the Triune nature of God.