Many cults like the Jehovah Witnesses deny the trinity. The Watchtower and bible tract society teach that Jesus was a created being the first and direct creation of Jehovah and all other things were created through him. I have had many street conversation with Jehovah Witnesses and when I ask them for a verse that says Jesus is a created being they often quote Colossians 1 : 15.
Colossians 1 : 15 – “He is the image of the invisible God,+ the firstborn of all creation” (New World Translation, Jehovah Witnesses own translation of the bible).
The Jehovah Witnesses understand firstborn to mean first created and then all other things were made through him.
“God created Jesus before creating Adam. In fact, God created Jesus and then used him to make everything else, including the angels. That is why the Bible calls Jesus “the firstborn of all creation” by God.”— Taken from jw.org (https://www.jw.org/en/publications/magazines/wp20130301/when-jesus-created-why-son/#?insight[search_id]=3d0bb731-75e3-49b6-8fc7-fe1a1e888531&insight[search_result_index]=0)
However this is what firstborn means and is this how the original audience of Colossians would have understood it. The book of Colossians was a epistle (letter) from Paul to the believers in Colosse (ch1 : 1 – 2). Paul was responding to some of the Gnostic teaching that was infiltrating the Church of Colosse. This teaching was that Jesus was a demigod. The Jehovah witnesses interpretation of this verse would confirm this teaching not speak against it.
The term firstborn is used elsewhere in the scriptures and refers to authority instead of genealogical. In Psalm 89 David is referred to as the firstborn.
“I have found David, my servant;
with my holy oil I have anointed him,
21 so that my hand shall be established with him;
my arm also shall strengthen him.
22 The enemy shall not outwit him;
the wicked shall not humble him.
23 I will crush his foes before him
and strike down those who hate him.
24 My faithfulness and my steadfast love shall be with him,
and in my name shall his horn be exalted.
25 I will set his hand on the sea
and his right hand on the rivers.
26 He shall cry to me, ‘You are my Father,
my God, and the Rock of my salvation.’
27 And I will make him the firstborn,
the highest of the kings of the earth”. (Psalm 89 : 20 – 27, ESV, emphasis added.)
However 1 Samuel 17 : 13 indicates that Eliab was the first born.
“he three oldest sons of Jesse had followed Saul to the battle. And the names of his three sons who went to the battle were Eliab the firstborn, and next to him Abinadab, and the third Shammah.” (1 Samuel 17 : 13, ESV)
The term firstborn 1 Colossians 1 : 15 in the Greek language is not referring to birth but to kingship, authority and preeminence. The first place in all things as the creator of all things. God assigned this title to David as it would be his lineage that the messiah would come. (Matthew ch 1).
The bible clearly teaches that Jesus was the creator of all things and not a created being. The bible identifies Jesus as Jehovah (Yahweh). An example of this can be seen in John chapter 12
John 12 is at the end of jesus public ministry.
“The reason why they were not able to believe is that again Isaiah said: “He has blinded their eyes and has made their hearts hard, so that they would not see with their eyes and understand with their hearts and turn around and I heal them.” Isaiah said these things because he saw his glory, and he spoke about him. All the same, many even of the rulers actually put faith in him, but they would not acknowledge him because of the Pharisees, so that they would not be expelled from the synagogue; for they loved the glory of men even more than the glory of God” (John 12 : 39 – 43, New World Translation).
Within these few verses there is a reference to Isaiah 6:10 which in the New World Translation is referenced to in the footnotes.
“Make the heart of this people unreceptive,+Make their ears unresponsive,+And paste their eyes together,So that they may not see with their eyesAnd hear with their ears,So that their heart may not understandAnd they may not turn back and be healed.” (Isaiah 6 : 10, New World Translation)
Isaiah 6 is a vision of Yahweh( Jehovah) in John he tributes this to Jesus. Isaiah identifies Yahweh as the one sitting on the throne. However John identifies Jesus as the one sitting on the throne. This is not a contradiction if the doctrine of the trinity is true.