Jehovah's Witnesses believe that the Trinity is of the devil, and that Jesus is a 'lesser god' than Jehovah God (they also believe that Jesus is Michael the Archangel).
Mormons believe that God the Father is made up of flesh and bone, and is an evolved human being, and that a 'good Mormon' can someday become a god and create their own universe. If you accuse them of polytheism (worshiping many gods), they will deny it and say that they only worship one god, because they only worship the god of THIS universe. But in fact, they actually are taught that there are countless billions of gods. They believe that Jesus and Satan are brothers, and that Jesus was sexually conceived by Jehovah God having sex with one of his many wives. They believe that the Holy Spirit is merely a force.
Although cults completely deny the Trinity, or change it into something completely different, many Christians get the Trinity wrong as well, and fall into error. There are various errors concerning the Trinity that Christians fall into. One such example is called Modalism.
Modalism is probably the most common theological error concerning the nature of God. It is a denial of the Trinity which states that God is a single person who, throughout biblical history, has revealed Himself in three modes, or forms. Thus, God is a single person who first manifested himself in the mode of the Father in Old Testament times. At the incarnation, the mode was the Son. After Jesus' ascension, the mode is the Holy Spirit. These modes are consecutive and never simultaneous. In other words, the Father, the Son, and the Holy Spirit never all exist at the same time, only one after another. Modalism denies the distinctiveness of the three persons in the Trinity, even though it retains the divinity of Christ. Present day groups that hold to forms of this error are the United Pentecostal and United Apostolic Churches. They deny the Trinity, teach that the name of God is Jesus, and require baptism for salvation. These modalist churches often accuse Trinitarians of teaching three gods. This is not what the Trinity is. The correct teaching of the Trinity is one God in three eternal coexistent persons: The Father, the Son, and the Holy Spirit.
Did Jesus exist before his human birth? What or who was Jesus before his incarnation? Was he the God of the Old Testament?
In order to understand who Jesus was, we first should understand the basic doctrine of the Trinity. The Bible teaches us that God is one and only one being. This tells us that whoever or whatever Jesus was before his human incarnation, he could not have been a separate God from the Father.
While God is one being, he exists eternally as three coequal and coeternal Persons, whom we know as the Father, the Son and the Holy Spirit. In order to understand how the Trinity doctrine describes the nature of God, we must keep in mind the difference between the words "Being" and "Person." This distinction has been put in the following terms: there is but one what of God (that is, his Being) but there are three whos within the one being of God, that is, the three divine Persons—Father, Son and Holy Spirit.
The Being we call the one God has an eternal relationship within himself of Father to Son. The Father has always been the Father and the Son has always been the Son. And, of course, the Holy Spirit has always been the Holy Spirit. One Person in the Godhead has not preceded the other, and neither is one Person inferior to the other in his essence. All three divine Persons—Father, Son and Holy Spirit—share the one being of God. The Trinity doctrine explains that Jesus was not created sometime prior to his incarnation, but existed eternally as God.
There are, then, three pillars to the Trinitarian understanding of God’s nature. First, only one true God exists, who is Yahweh (YHWH) of the Old Testament or theos of the New Testament—the Creator of all that exists. The second pillar of this teaching is that God is made up of three divine Persons, who are the Father, the Son, and the Holy Spirit. The Father is not the Son, the Son is not the Father or Holy Spirit, and the Spirit is not the Father or the Son. The third pillar tells us that these three distinct (but not separate) persons equally share the one divine being, God, and that they are eternal, co-equal and co-essential. Thus, God is one in essence and one in being, but exists in three persons. (We must always be careful not to understand the "Persons" of the Godhead like persons in the human sphere, where one person is separate from another.)
It is acknowledged that there is something about God as Trinity that transcends our finite understanding. Scripture does not explain how it is that the one God can exist as the Trinity. It only affirms that this is so.
Granted, how the Father and the Son can be one being seems difficult for us humans to understand. That’s why it’s important to keep in mind the distinction between person and essence, which the doctrine of the Trinity makes. This distinction tells us that there is a difference between the way God is one and the way that he is three. Simply put, God is one in essence and three in persons. If we keep that distinction at the front of our discussion, we will avoid being confounded by the seeming (but not real) contradiction in the biblical truth that God is one being in three Persons—Father, Son and Holy Spirit.
A physical analogy, though an imperfect one, might help us understand. There is but one pure light, and that is white light. But white light can be broken down into three primary colors—red, green and blue. Each of the three primary colors does not exist apart from the other primary colors—they are included within the one light, which is white. There is but one complete light that we call white light, but this light contains three distinct but not separate primary colors.
The above explanation gives us the essential basis of the Trinity, which provides the perspective to understand who or what Jesus was before he became human flesh. Once we understand the relationship that has always existed within the one God, we can proceed to answer the question of who Jesus was before his incarnation and physical birth.
Jesus’ Eternality and Pre-Existence in John’s Gospel
The pre-existence of Christ is clearly stated in John 1:1-4: "In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through him all things were made; without him nothing was made that has been made. In him was life…" It is this Word or Logos in Greek who became incarnate in Jesus. "The Word became flesh and made his dwelling among us," John tells us (verse 14).
The eternal, uncreated Word who was God, and yet was with God as one of the Persons of the Godhead, became a human being. Note that the Word "was" God but "became" a human being. The Word never came into being, that is, he didn’t "become" the Word. He always was the Word, or God. The Word’s existence is open-ended. He has always existed.
As Donald Macleod points out in The Person of Christ: "He is sent forth as one who already has being, not as one who comes into being by being sent" (page 55). Macleod further states: "In the New Testament, Jesus’ existence as a man is a continuation of his previous or prior existence as a heavenly being. The Word who dwelt among us is the same as the Word who was with God. The Christ who is found in form as a man is the very one who previously existed in the form of God" (page 63). It is the Word or the Son of God who takes flesh, not the Father or the Holy Spirit.
In the Old Testament, the most common name for God is Yahweh, which comes from the Hebrew consonants YHWH (called a tetragrammaton). It was Israel’s national name for God, the ever-living, self-existent Creator. In time, the Jews began to consider the name of God, YHWH, as too sacred to be pronounced. The Hebrew word adonay ("my Lord") or Adonai was substituted. Hence, in English Bibles, we see the word "Lord" used where YHWH appears in the Hebrew Scriptures.
Yahweh is the most common name of God found in the Old Testament, being used over 6800 times in reference to him. Another name for God in the Old Testament is Elohim, which is used over 2500 times, as in the phrase "the Lord God" (YHWH Elohim).
In the New Testament, there are many scriptures where the writers apply to Jesus passages that were written in reference to Yahweh in the Old Testament. The practice of the New Testament writers is so common that its significance may escape us. By using Yahweh scriptures for Jesus, these writers are implying that Jesus was Yahweh, or God, made flesh. Of course, we shouldn’t be surprised that the writers make this comparison, because Jesus himself explained that Old Testament passages applied to him (Luke 24:25-27, 44-47; John 5:39-40, 45-46).
John makes a clear connection between Jesus and Yahweh, the name of God in the Old Testament. But John does not equate Jesus with the Father (and neither do the other Gospels). Jesus, for example, prays to the Father (John 17:1-15). John understands that the Son is distinct from the Father—and he also sees that both are distinct from the Holy Spirit (John 14:15, 17, 25; 15:26). Since that is so, John’s identification of Jesus as God, or Yahweh (if we think of his Hebrew, Old Testament name), is a Trinitarian explanation of God’s being.
In John’s Gospel, Jesus tells his disciples: "I am telling you now before it happens, so that when it does happen you will believe that I am He" (13:19). The phrase "I am He" is translated from the Greek ego eimi. The phrase occurs 24 times in John’s Gospel. At least seven of these are said to be "absolute" in that they are not followed by a predicate, such as in John 6:35, "I am the bread of life." In the seven absolute cases, no predicate follows, and the "I AM" phrase comes at the end of the clause. This indicates that Jesus is using this phrase as a name to identify who he is. The seven places are John 8:24, 28, 58; 13:19; 18:5, 6 and 8.
If we go back to Isaiah 41:4, 43:10 and 46:4, we can see the background for Jesus’ reference to himself in John’s Gospel as ego eimi ("I AM"). In Isaiah 41:4, God or Yahweh says: "I, the Lord…I am he." In Isaiah 43:10 he says "I am he," and later says, "‘You are my witnesses,’ declares the Lord, ‘that I am God’" (verse 12). In 46:4, God (Yahweh) again refers to himself as "I am he."
The Hebrew phrase "I am he" is translated in the Greek version of the Holy Scriptures, the Septuagint (which the apostles used), by the phrase ego eimi in Isaiah 41:4; 43:10; and 46:4. It seems clear that Jesus’ made the "I am he" statements as references to himself because they directly connected to God’s (Yahweh’s) statements about himself in Isaiah. John said, in effect, that Jesus was saying he was God in the flesh (John 1:1, 14, which introduces the Gospel and speaks of the Word’s divinity and incarnation, prepares us for this fact.)
John’s ego eimi ("I Am") identification of Jesus can also be carried back to Exodus 3, in which God identifies himself as the "I Am." Here we read: "God [Hebrew, elohim] said to Moses, ‘I AM WHO I AM. This is what you are to say to the Israelites: "I AM has sent me to you"’" (verse 14).
John repeats Jesus’ identification of himself as the "I AM" of the Old Testament. Since there is but one God, and John would have understood that, then we are left with the proposition that there must be two persons sharing the one nature that is God. With the Holy Spirit, also discussed by John in chapters 14-17, we have the basis of the Trinity.
To put aside all doubt about John’s identification of Jesus with Yahweh, we may quote John 12:37-41, which says:
Even after Jesus had done all these miraculous signs in their presence, they still would not believe in him. This was to fulfill the word of Isaiah the prophet: "Lord, who has believed our message and to whom has the arm of the Lord been revealed?" For this reason they could not believe, because as Isaiah says elsewhere: "He has blinded their eyes and deadened their hearts, so they can neither see with their eyes, nor understand with their hearts, nor turn—and I would heal them." Isaiah said this because he saw Jesus’ glory and spoke about him.
The quotes above that John used come from Isaiah 53:1 and 6:10. The prophet originally spoke his words in regards to Yahweh. John says that what Isaiah actually saw was "Jesus’ glory" and that he "spoke of him." For John the apostle, then, Jesus was Yahweh in the flesh; before his human birth he was known as Yahweh.
(Most of the above information is from: http://www.wcg.org/lit/jesus/whowas.htm)