The following was taken from www.jewsforjudaism.org
Question: Isaiah 9:5-6 says: "For a child has been born to us, a son has been given to us; and the government is upon his shoulder; and his name is called A wonderful counselor is the mighty God, the everlasting Father, the ruler of peace; that the government may be increased, and of peace there be no end, upon the throne of David, and upon his kingdom, to establish it, and to uphold it through justice and through righteousness from henceforth even forever. The zeal of the Lord of hosts does perform this." Who is the child the prophet speaks about?
Answer: Isaiah is known for the method by which he presents many of his messages through the use of prophetic names (Isaiah 7:3, 14; 8:3). In the verse under study, the prophet expounds his message by formulating a prophetic name for Hezekiah. The words of this name form a sentence expressive of God's greatness, which will become manifest in the benefits to be bestowed upon the future king in his lifetime. Thus, the name, though borne by the king, serves, in reality, as a testimonial to God.
Hezekiah is called "a wonderful counselor" because this name is a sign, which foretells God's design for him.
The Lord of hosts has sworn, saying: "As I have thought, so shall it be, and as I have purposed, so shall it stand, that I will break Asshur in My land, and upon My mountains trample him under foot; then shall his yoke depart from off them, and his burden depart from off their shoulder." This is the purpose that is purposed upon the whole earth; and this is the hand that is stretched out upon all the nations. For the Lord of hosts has purposed, and who will annul it? And His hand is stretched out, and who shall turn it back? (Isaiah 14:24-27) Be not afraid of the words that you have heard, with which the servants of the king of Assyria have blasphemed Me. Behold, I will put a spirit in him, and he shall hear a rumor, and shall return to his own land; and I will cause him to fall by the sword in his own land. (Isaiah 37:6-7)
Hezekiah is called "the mighty God" because this name is a sign that foretells God's defense of Jerusalem through the miraculous sudden mass death of Sennacherib's army.
Therefore thus says the Lord concerning the king of Assyria: He shall not come to this city, nor shoot an arrow there, neither shall he come before it with shield, nor cast a mound against it. By the way that he came, by the same shall he return, and he shall not come to this city, says the Lord. For I will defend this city to save it, for My own sake, and for My servant David's sake. (Isaiah 37:33-35) Hezekiah is called "the everlasting Father" because this name is a sign, which foretells that God will add years to his life. "Go, and say to Hezekiah: Thus says the Lord, the God of David your father: I have heard your prayer, I have seen your tears; behold, I will add to your days fifteen years" (Isaiah 38:5).
Hezekiah is called "the ruler of peace" because this name is a sign, which foretells that God would be merciful to him. Punishment for lack of faith in the Almighty will be deferred and peace granted during the last years of his rule. "Then said Hezekiah to Isaiah: 'Good is the word of the Lord which you have spoken.' He said moreover: 'If but there shall be peace and security in my days'" (Isaiah 39:8).
The fulfillment of the above-stated declarations is foretold in Isaiah 9:6, when, after the Assyrian defeat, Hezekiah's glory increased and peace reigned for the rest of his life (2 Chronicles 32:23). Archaeologists have found that there was a sudden expansion of Judean settlements in the years following the fall of the northern kingdom. This indicates that many refugees fled south, thus giving added significance to the statement "that the government may be increased."
Hezekiah's kingdom is declared to be forever, for through his efforts to cleanse the Temple ritual of idolatry, even though apostasy followed under his son Menasseh, the Davidic dynasty was once more confirmed as the only true kingly rule that God would accept over his people "from henceforth and forever." The greatness of Hezekiah lies in his setting the stage for Israel's future. Hezekiah was a true reformer. He cleansed religious worship of foreign influence, purged the palace and the Temple of images and pagan altars, and reestablished pure monotheistic religion.
In the long run Hezekiah's achievements would outlive him, leaving an everlasting, indelible impact on the history of his people. Thus, God, through Isaiah, bestows upon Hezekiah this name which honors the king by proclaiming the great things God will do for him, and, through him, for the people of Israel.
Question: Can you give a reason why Jews say Isaiah 9:6 does not refer to Jesus?
Answer: Christian theologians argue that the name "A wonderful counselor is the mighty God, the everlasting Father, the ruler of peace" refers to Jesus, who they allege combined human and divine qualities. They mistakenly believe that such a name can only be applied to God Himself. Moreover, the Christians incorrectly translate the verbs in verse 5 in the future tense, instead of the past, as the Hebrew original reads. Thus, the Christians render verse 5 as: "For a child will be born to us, a son will be given to us; and the government will rest on his shoulders; and his name will be called Wonderful Counselor, Mighty God, Eternal Father, Prince of Peace."
While admitting that "wonderful counselor" and "ruler of peace" can be applied to a man, Christian theologians argue that the phrases "mighty God" and "everlasting Father" cannot be incorporated as part of a man's name. Thus, they contend that Isaiah teaches that the Messiah has to be not only a man, but God as well. That this entire reasoning is incorrect may be seen from the name Elihu, "My God is He," which refers to an ordinary human being (Job 32:1, 1 Samuel 1:l, 1 Chronicles 12:21, 26:7, 27:18). A similar Christian misunderstanding of Scripture may be seen in their claims revolving around the name Immanuel, "God is with us." The simple fact is that it is quite common in the Bible for human beings to be given names that have the purpose of declaring or reflecting a particular attribute of God, e.g., Eliab, Eliada, Elzaphan, Eliakim, Elisha, Eleazar, Tavel, Gedaliah.
The fact remains that Jesus did not literally or figuratively fulfill any of Isaiah's words. A wonderful counselor does not advise his followers that if they have faith they can be agents of destruction (Matthew 21:19-21; Mark 11:14, 20-23). A mighty God does not take orders from anyone (Luke2:51, Hebrews 5:8), for no one is greater than he is (Matthew 12:31-32; John 5:30, 14:28). Moreover, he does not ask or need to be saved by anyone (Matthew 26:39, Luke 22:42), for he cannot die by any means (Matthew 27:50, Mark 15:37, Luke 23:46, John 19:30). He who is called the Son of God the Father (John 1:18, 3:16) cannot himself be called everlasting Father. One cannot play simultaneously the role of the son and the Father; it is an obvious self-contradiction. He who advocates family strife (Matthew 10:34-35, Luke 12:49-53) and killing enemies (Luke 19:27) cannot be called a ruler of peace.
Back to the "God" title given to Jesus in Isaiah 9:6 was given to others before him in the Bible.