Is Yahweh or Yehovah the "Name of the LORD"? Is Yeshua or Yahshua the name of the "Son" and Messiah?
Yahweh (Jehovah) is certainly “a” name of God. There are other names given in the Bible. When Moses asked for God’s name, he was told that it was “Hayah Hayah” (“I exist, I exist” or “I am that I am”). (Exodus 3:14) Other places give him other names or descriptions. Perhaps the longest “name” of God in the Bible is found in Amos 3:13, where he is called “the Lord God, the Lord of Hosts” (Adonay Yahweh Elohim Tsaba). This uses three of the most common names of God in the Hebrew language. Keep in mind, though, God’s name is also Theos. It is also God. It depends on what language you are speaking which one you may use.
Yeshua (Jesus, Joshua) was the name the Son of God used while on Earth. That is because the name means “savior.” “And thou shalt call his name Jesus, for he shall save his people from their sins.” (Matthew 1:21) After his death, we almost always find the New Testament writers referring to him by both his name and title, Jesus Christ (in Hebrew, Jeshua ha Moshiach).