Is there a clear reference to the Trinity in the New Testament? According to several versions, there is indeed!
For there are three that bear witness in heaven: the Father, the Word, and the Holy Spirit; and these three are one. And there are three that bear witness on earth: the Spirit, the water, and the blood; and these three agree as one. (1 John 5:7,8 NKJV)
And the following versions translate it similarly:
AKJV, AV, Douay, JB2000, NKJV, Webster, and YLT (although YLT place the Trinity words in italics).
However, consider the following translation:
For there are three that testify: the Spirit and the water and the blood; and these three agree. (1 John 5:7,8 ESV)
Translating it similarly are the following versions:
ASV, BBE, Darby, Diaglot, EMTV, HCSB, LO, NAS95, NIV, RSV, and Wey
So how do we know which translations are correct? Actually, both are correct, considering the Greek manuscript that each translator used as his source.
The first translation is of Greek manuscripts that contain the words:
For there are three that bear witness in heaven: the Father, the Word, and the Holy Spirit; and these three are one.
These words are known as “The Johannine Comma”.
Here are some facts, which taken together make it almost impossible to maintain that The Johannine Comma was part of the original letter which we call “1st John”.
1. Out of the many hundreds of manuscripts which contain 1st John, there are only eight known Greek manuscripts which contain the passage.
2. Of the eight, four of them include it not as part of the text, but as a marginal note.
3. Seven of the eight date from the 15th to 18th centuries.
4. The other one is a variant reading of a 10th century manuscript.
5. During the Trinitarian controversies of the 4th and 5th centuries, no Greek father quoted the passage in support of Trinitarianism. Was that because it did not exist at that time?
If the passage were original, how can it be explained that it was absent from the many hundreds of
early Greek manuscripts, and not present in even one of them?
Further details about the Johannine Comma can be obtained from:
http://www.bible-researcher.com/comma.html