This Side of the Trinity?

I heard on the radio that Christians are to spread the gospel, being on this side of the “Trinity.” The speaker was implying that Christians need to believe in the “Trinity." How does that work for those who were first called Christians in the first century when then Anthanasian Creed that depicts “The Son is God” was birthed in AD 325? “And the disciples were first called Christians in Antioch.” Acts 11:26 (NKJV) The Anthanasian Creed is manmade, and most definitely on the wrong side of Jesus’s teachings. There’s no reason to believe that anyone has to believe the doctrine of the “Trinity,” in order to be a true follower of Christ Jesus. God bless. In His Care… Jim