It is tiresome to see the Trinity derided as a sinister invention because it is not in the Bible. Do you think the early Christians didn’t know that? Terms are often invented as a form of shorthand to describe doctrines– Virgin Birth, Justification, Amillenialism, Dispensationalism, etc. For that matter, this is the whole point of inventing terms for anything. It’s easier to say “grand slam” than “home run with three runners on base.”
The Trinity is a concept taught in multiple places in the Bible.