I believe God's word, not men's words. The Trinity was made up by men hundreds of years after the Apostles died. The Apostles did not teach the Trinity, and that is very clear from the Bible. According to the Apostles it is heretical to believe in the Trinity.
That verse can be applied to anyone who believes in the Trinity. As Jude wrote (1:3), "I was constrained to write to you exhorting you to contend earnestly for the faith which was
once for all delivered to the saints". Nothing should be added or removed to the faith that Jesus and the Apostles taught. The Trinity was a later addition.
And how many times have those people ignored the clear plain truth that the Apostle Paul taught? - 1 Corinthians 8:6 (WEB):
(6) yet to us there is one God, the Father, of whom are all things, and we for him; and one Lord, Jesus Christ, through whom are all things, and we live through him.
And what Jesus taught - John 17 (WEB):
(1) Jesus said these things, and lifting up his eyes to heaven, he said, “Father, the time has come. Glorify your Son, that your Son may also glorify you;
(3) This is eternal life, that they should know you, the only true God, and him whom you sent, Jesus Christ.
and John 20:17 (WEB):
(17) Jesus said to her, “Don’t hold me, for I haven’t yet ascended to my Father; but go to my brothers, and tell them, ‘I am ascending to my Father and your Father, to my God and your God.’”
I don't ignore or deny those verses - I believe them.