Some three hundred years after the apostle John completed the last books of the New Testament (c. 98 C.E.), a writer (c. 400 C.E.) seeking to strengthen the Trinitarian doctrine added the addition (interpolation) to 1 John 5:7: “in heaven, the Father, the Word, and the Holy Ghost: and these three are one.” This statement was not in the original.
MODERN textual scholars do not hesitate to omit from the Bible the spurious passage found at 1 John 5:7-8. It is omitted by the translations ERV, ASV, RSV, ESV, NASB, LEB, CSB, UASV, etc.) Commenting on these words, the greatest textual scholar of the 20th century Bruce M. Metzger said, "these words are spurious and have no right to stand in the New Testament is certain ..." - Textual Commentary on the Greek New Testament (1994), 647.