Hello Jason, you say that the Doctrine of the Holy Trinity, is "man-made", which means that you reject this as being taught in the Holy Bible?
While I would admit that the actual term "Trinity" is no where in the Bible, but, what it means and teaches, is very clearly based on Bible Facts. The term itself is a compound word, from "tri=three", and (u)nity". This is use to show that though the Bible teaches that there is only One God, that is, the Godhead (Romans 1:20, "θειότης", "the divine nature"). The Bible also teaches that there are Three Persons Who are called "God", and are "coequal, coessential, and coeternal". The very first verse of Genesis chapter one, has, "in the beginning God created", where the Hebrew for "God", is "Elohim", which is masculine in gender, and plural in number. Some have thought that this simply means, "a plural of majesties", as in when the King or Queen of a country says "we", (the royal "we"). But verse 26 of this same chapter in Genesis, and other places, clearly show that "plurality of Persons" is meant, "Let US make man in OUR image". In Isaiah 54:5, God is referred to as "Maker", where the Hebrew is plural, "Makers", which can only be used to show that more than One Person is meant. Jesus Himself says in John 10:30, "ἐγὼ καὶ ὁ πατὴρ ἕν ἐσμεν", literally, "I and the Father one We are". Here we have Jesus as the Speaker, Who is seen as a "separate" Person to the Father, where the use of the Greek definite article, "ὁ" (the), is used for this purpose. We then have the use of the Greek, "ἕν", "one", which is in neuter in gender, and singular in number, literally "one thing", on in this context, "one essence". Then we have "ἐσμεν", which is masculine in gender, and plural in number, which shows the "plurality of Persons", Who are "united in essence". The fact that Jesus Christ is Almighty God, can be seen from Scriptures like Isaiah 9:6, where He is called, "el gibbor", that is, "Mighty God"; the same Title which is used for Yahweh (the Father), in Isaiah 10:21. In John 1:1, we read that "the Word was with God", where the use of the Greek preposition, "πρὸς", can only be used for more than one Person, as it denotes, "besides, in the presence of", "WITH God", making Jesus (the Word) a "separate" Person to the "God" (the Father) He was with. The verse then goes on to say, "καὶ θεὸς ἦν ὁ λόγος" (and God was the Word). John very carefully did not write, "καὶ ὁ θεὸς ἦν ὁ λόγος", which would have contradicted his previous statement, as this would have made the "Word", equivalent to the "Person" of the "God" Who He was "πρὸς", whereas the previous statement (καὶ ὁ λόγος ἦν πρὸς τὸν θεόν, = and the Word was with God), shows a "distinction in Persons". John, by not using the article "ὁ", with "θεὸς", is showing that the "Word", Jesus Christ, is Deity, in exactly the same way that the Father is. Here we have Two Persons Who are equally God. In Acts chapter 5 we read of the account of Ananias and Sapphira, who together lied about the sale of their possessions. Peter, in addressing this issue, says to Ananias, "why hath Satan filled thine heart to lie to the Holy Spirit" (v.3), and then goes on to say, "you hast not lied unto men, but unto God" (v.4), where the Greek has it, "τῷ θεῷ", which cannot be reduced to "god", or "a god", but has to read, "God". Thereby showing the Deity of the Holy Spirit. In Matthew 28:19, we read the words of Jesus Christ, "Go ye therefore, and teach all nations, baptizing them in the Name of the Father, and of the Son, and of the Holy Spirit". The Greek is very important here. We have the use of the singular, "τὸ ὄνομα" (the Name). Then, we have, "τοῦ πατρὸς καὶ τοῦ υἱοῦ καὶ τοῦ ἁγίου πνεύματος" (the Father and the Son and the Holy Spirit), where the Greek article "τοῦ", is repeated, with each Person, which shows their "distinction". "τὸ ὄνομα", is used here as the equivalent to the Name that Moses was given by God, in Exodus 3:14-15, "And God said unto Moses, I AM THAT I AM: and he said, Thus shalt thou say unto the children of Israel, I AM hath sent me unto you. And God said moreover unto Moses, Thus shalt thou say unto the children of Israel, The LORD God of your fathers, the God of Abraham, the God of Isaac, and the God of Jacob, hath sent me unto you: this is my Name for ever, and this is my memorial unto all generations". The Name here spoken of, is YHWH (Yahweh). The Father, Son and Holy Spirit have the same Name, YHWH, which makes them equally Almighty God.
This is the Biblical Teaching on the God of the Holy Bible. One Godhead, Three Persons.
