Simply because the Son of God is called the “mighty God” here in Isaiah 9:6 does not entail that He is Jehovah. For JWs, the “mighty God” is not the “Almighty God” (cf. Aid to Bible Understanding [Watchtower Bible and Tract Society, 1971], 919).
Isaiah 1:24 has already declared that “the Mighty One of Israel” is none other than Jehovah (“LORD”). Isaiah 10:20-22 says that Jehovah is the “mighty God.” Deuteronomy 7:21 calls Jehovah “mighty God.” Jeremiah 32:18 also says, “The Great, The Mighty God, The LORD of hosts, is his name.” Thus, the Bible knows no distinction between the mighty God and the Almighty God. Therefore, using the law of transitivity (if a=b, and b=c, then a=c), the Son of God is the Almighty God.
Furthermore, if Jesus is not the Almighty, then He's a false God. Psalm 96:5 says that all the gods of the people are idols, but Jehovah made the heavens. John 17:3 says that there only one true God. So if Jesus isn't this true God, then He must be a false god. However, we know that Jehovah not only made the heavens, but He made them "alone" as Isaiah 44:24 says, and Jesus is identified as the maker of all things just as the Father is (Jn. 1:1-3, 14; 1 Cor. 8:6; and Col. 1:13-18). Thus, Jesus is the Almighty just as the Father is. Jesus even claimed He was the Almighty in Revelation 1:7-8, 17-18 and 22:6, 12-20.
R. M. Sivulka
President, Courageous Christians United