Why is the name Jesus or the title Christ not found in the Old Testament but the name Immanuel is?

Answer 1

The question arises out of a natural confusion across probably four different languages: English, the language in which we read The Bible, Greek, the language in which the New Testament was written, and Hebrew and Aramaic, the languages of the Old Testament. Greek was also the language of the Septuagint, an early and flawed translation of the Hebrew scriptures, which has led to some of this confusion.

Jesus is the Greek equivalent to Joshua, a common name in the Old Testament. Because the New Testament was written in Greek, we have in it the name Jesus, rather than Joshua. The Hebrew name for Joshua was (approximately) transliterated into English without conversion to the Greek equivalent.

In a somewhat similar way, Christ is the Greek word for "the anointed one" and corresponds to the Hebrew word for Messiah, common in the Old Testament.

Immanuel is found in the Book of Isaiah, but did not really refer to Jesus at all. The author of Matthew's Gospel knew that the Septuagint referred to a virgin who would have a baby and his name shall be Immanuel. He apparently did not realise that the Septuagint was wrong, because the correct translation did not mention a virgin; it should have been "the young woman" and she di have a baby just a few verses later in the Book of Isaiah.