That is the power of propaganda and disinformation. Westcott & Hort perpetrated a hoax on Christendom, and very few protested against it and rejected the Revised Version (RV) of 1881. Today that version lies in the dust
1 John 5:7 is authentic Scripture and once it is removed from that passage, the passage makes absolutely no sense (just like the removal of John 7:53-8:11 destroy the sense of that section of the Gospel). But even Jerome's Latin Vulgate completed around AD 380 has this verse (subsequently corrupted in the newer editions). And the Bishop's Bible of 1568 also has this verse.
LATIN VULGATE
Quoniam tres sunt, qui testimonium dant in cælo: Pater, Verbum, et Spiritus Sanctus: et hi tres unum sunt.
BISHOPS' BIBLE
For there are three which beare recorde in heauen, the father, the worde, and the holy ghost, and these three are one.
KING JAMES BIBLE
For there are three that beare record in heauen, the Father, the Word, and the holy Ghost: and these three are one. (original words)
For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one. (standard text)
So we can rest assured that there is overwhelming support for a very important verse which plainly declares that the Holy Trinity is in Heaven.