The Trinity?

The only verse in the entire Bible that explicitly describes the "trinity" is 1 John 5:7-8
Unfortunately this version is a Latin corruption that is not found in any manuscript prior to the 14th century. See Comma Johanneum

Quoting from the description the Trinity is... "one God in three persons: while distinct from one another in their relations of origin and in their relations with one another, they are stated to be one in all else, co-equal, co-eternal and consubstantial, and "each is God, whole and entire." 

Let's examine some of this...
Co-Equal :
For Jesus and the Holy Spirit to be 'co-equal' they would have to have all the same properties of God.
Who is God? - here is my post on the qualities of God.
Is Jesus God?(1) , Is Jesus God?(2) - These posts clearly show Jesus is not and that he explicitly states he is not.

Now as the Holy Spirit... The definition of the Holy Spirit is "a spirit without impurities". In essence it is God. God's at work in most cases. No where does it mention people talking to the Holy Spirit, or the Holy Spirit talking or instructing others. It is always mentioned as 'filled with the Holy Spirit' or 'in the name of the Holy Spirit'.

The belief that the Advocate mentioned in the Gospel of John chapters 14-16 is the Holy Spirit promised to come after the death of Jesus, implies that the Holy Spirit has not come yet.
In Luke 3:21-23 the Holy Spirit comes down during Jesus' baptism.
Many other mentions of the Holy Spirit are in the gospels, which makes John's passages about the advocate associate with the Holy Spirit confusing.

Also to note Jesus did say go and baptize in the name of the  Holy Spirit, yet this clearly contradicts Acts 19:1-2 when the disciples of Jesus who were baptized by John the baptist, state “No, we have not even heard that there is a Holy Spirit.”   

Co-Eternal: 
There are a couple verses that mention Jesus speaking about being before Abraham, also that he is the Word and the Word became flesh. There is not doubt that the implied message from the author of the gospel of John is elevating Jesus to a divine status. But if you are to take these passages as truth and disregard all other passages then you are denying that the Bible is an entire truth.

There are doctrines that state because of these verses Jesus states he was there during creation, yet they completely ignore verses that contradict that. ie. (Isaiah 44:24)
"I am the Lord, the Maker of all things, who stretches out the heavens, who spreads out the earth by myself" 
By His self, can't get any more contradictory than that.

Arius "If Jesus was in reality the "Son of God", then it followed that the Father must have existed before him(the Son), therefore, there must have been a time where the Son(Jesus) did not exist. Therefore, it followed that the Son was a creature composed of an essence or being which had not always existed. Since God is in essence eternal and ever-existing, Jesus could not be of the same essence of God."