Tell us what you think the Trinity even is, brother...
Well, first I want to say that I have the upmost respect for those who may hold a different view than myself because I was raised in a Trinitarian church and am still really close to the saints and pastor of that church, as well as others.
However I believe that Paul was speaking prophetically in Col. 2:8-9 that there would come a day when it would be taught that the fulness of the Godhead did not dwell in Christ.
If you study Church history from around 250AD to the present, it appears that the Trinity is a very Orthodox view.
However, if you study Church history prior to the third century, the picture looks much different. History teaches that prior to the day of a man by the name of Tertullian, the doctrine of the Trinity didn't exist.
Although there were discussions and disputes about the Godhead even back then, the Trinitarian concept wasn't widespread until Tertullian, even though his concept of the Trinity was much different than that was developed and confirmed at the Counsel of Nicea in 320 AD.
Prior to 100AD even secular church history confirms that all believers were baptized in the name of Jesus Christ, with those exact words pronounced over them.
When the book of Mathew was written in approx. 63AD, ALL believers were baptized in the name of Jesus Christ, and still were for atleast another 50+ years, until the apostles died off and their successors and other teachings began to come in. To that date, hundreds of thousands of people continued to be baptized in Jesus' name and no other way.
To them Math. 28:19 was not a contradiction to how they baptized in the book of Acts, and for the next 100 years, but a confirmation. To them, when Jesus told them to baptize in the NAME of the Father, Son, and Holy Ghost, I believe they knew what that name was, so they baptized in the name of Jesus, confirming also Paul's statement in Col. 2:9
Those who sat on the Counsel of Nicea were NOT men who were even qualified to make any decisions on who God was. They were very paganistic, political "Christians" who believed a very compromised version of Christianity to what you and I believe today, which would later become known to us as Roman Catholicism.
In short, I believe that the doctrine of the Trinity is the one Catholic doctrine that most of Reformed Christianity hasn't YET let go of.