Is Jesus actually "the God" of the Old Testament? Why is this research controversial?

The New Testament declares very clearly that Jesus is the one who created the Universe and everything in it, and it does so in several places, such as Hebrews Chapter 1 and Colossians 1:15-16. The same New Testament declares that Jesus is God in the flesh. But what influence do Ancient Jewish religious beliefs about God that predate Jesus' being born on earth have to do with the New Testament? Where did the Apostles and other New Testament writers get their ideas? Was it from Jesus himself? Yes, Did culture and traditional views of God at the time (some of which do not hold sway today), have any impact on the New Testament writers? Yes, of course they did. Also, there was some "Divine Revelation", and there also was an important Bible study with Jesus after his resurrection in which, "And beginning with Moses and all the Prophets, he interpreted to them in all the Scriptures the things concerning himself." Luke 24:27.

The New Testament doesn't clarify which Bible translation Jesus used…