Denying the Trinity is a tradition of men
Arius
Nestorius
Sabellius
Eutyches
Apollinarius
and a few other people who either denied the Trinity, or taught a heretical Christology.
In Erie/Scott
PS Do you believe the Father, the Son, and the Holy Spirit are The Trinity of Three Persons in One God? Denying that belief is a "tradition of men".
You missed the point of the verse. Here, I'll post it again.
8 Beware lest anyone cheat you through philosophy and empty deceit, according to the tradition of men, according to the basic principles of the world,
and not according to Christ. (Colossians 2:8)
If it is a tradition of men that is according to Christ, that is, a teaching that is in accordance with (comes from) scripture, then it is not
essentially a tradition of men at all, since it came from God, not tradition. The traditions of men which mean nothing to me are those which are in addition to scripture.
6 Now these things, brethren, I have figuratively transferred to myself and Apollos for your sakes, that you may learn in us not to think beyond what is written, that none of you may be puffed up on behalf of one against the other. (1 Corinthians 4:6)
2 You shall not add to the word which I command you, nor take from it, that you may keep the commandments of the Lord your God which I command you. (Deuteronomy 4:2)
32 Whatever I command you, be careful to observe it; you shall not add to it nor take away from it. (Deuteronomy 12:32)
5 Every word of God is pure; He is a shield to those who put their trust in Him.
6 Do not add to His words, Lest He rebuke you, and you be found a liar. (Proverbs 30:5-6)
18 For I testify to everyone who hears the words of the prophecy of this book: If anyone adds to these things, God will add to him the plagues that are written in this book;
19 and if anyone takes away from the words of the book of this prophecy, God shall take away his part from the Book of Life, from the holy city, and from the things which are written in this book. (Revelation 22:18-19)