[pinkpanther]

Cool.

So there, we know that they forged that verse and put it into the Bible, and for many centuries, it was read by millions of Christians thinking it was the word of God.

Can you call those forged verses a corruption?

It is not even corruption
1 John 5:7-8 is not a forgery in the sense of being a deliberate falsification of the original text of the Gospel of John. It is a later addition to the letter of 1 John, included in some manuscripts but omitted by most modern translations because of its lack of support in the older manuscripts....