There is so much info out there it is hard to get accurate information! I was reading Prepared to Answer (by Gordon Ferguson) in its section on Jehovah’s Witnesses. Here the author referred to the name "Jehovah" or Yahweh as refering to the Godhead or Father Son and Holy Spirit. How would I find the definition for those names? Can I accuratly defend the deity of Jesus Christ by referring to him as Jehovah?
The Hebrew text has more than one name for God. It includes Elohim and Adonai. The Jews considered the name YHWH (the actual original Hebrew), as used originally in Exodus 3:14 as the most sacred of the names of God. They held the name in such high regard, they considered it to have mystical powers in and of itself. Eventually, they refused to actually pronounce this name.
The JWs have picked up on this fact and manipulated it into a reason to distinguish themselves from others who believe in Jesus. (Of course, they do not really believe in Jesus, but that is another point). They claim that YHWH is the only name God has ever used, illogically making this into an excuse to say that Jesus is not deity. A couple of problems here. First, the JWs, unfortunately for them, used a German transliteration of YHWH, Jehovah, as their unique name for God. Jehovah is fairly close to that actual Hebrew word, which is, approximately, with its vowels added Yahweh. Their entire doctrine is based on the use of a name which is not even all that close to the actual name God gave Moses in Exodus!
All that aside, is it proper to call Jesus Jehovah? That is a bit questionable. The Bible clearly shows Jesus to be God. He is part of the (to use a really fance word) "godhead." He is deity. Colossians 1 and Hebrews 1, along with dozens of other passages make it clear that Jesus is God. If Jesus is God and if God used the name YHWH, then logically one could justify calling Jesus YHWH. Having said that, the Hebrew Bible does not use the word Jesus and the New Testament does not use the word Jehovah (or YHWH or yahweh). For this reason, it would be a bit creative to use the name Yaweh for Jesus. I do not think names are the big issue here. I do not think Jesus would become all that worried what we call him, as long as we honor him as who he is. I would definitely not call Jesus Jehovah. You certainly would not win any points with the Jehovah Witness group doing that. I see no reason to do this, but do not think it is sinful or wrong to refer to Jesus as Jehovah.