As a Trinitarian Pentecostal, I agree with you about the Oneness sect, but believing and standing on the Word alone, will NEVER seem wrong to me. In another state, I was a member of the Evangelical Covenant Church, whose creed is, “What does the Bible say?”. Personally, I can worship in any church which preaches Jesus Christ and Him crucified. I don’t have to agree with all other points, though I have strong beliefs on those other points. If I don’t agree with every single one of the teachings, big deal. I go to worship and pray. As long as the church believes in the Deity of Christ, his death, burial, resurrection, and ascension, the infallibility of the Word as originally written, and His coming return, I’m good. I could easily worship in a Catholic church, though I would not participate in their communion. Firstly because I know it would be against their rules, but also because I do not agree with their doctrine of transubstantiation, NOT because I would think I was sinning by partaking. I could NOT, however, worship in a Mormon or Jehovah Witness gathering, because they don’t believe in the Deity of Christ or the atonement.
I can agree with you in about everything you state here.
But I do have a problem with that word; since we've NO idea what the 'original' stuff said.
All we have is very old copies that hopefully have carried the important stuff to us.