There is no question now and there will be no question in the millennium and for eternity that Christ is and will be fully God. And one of His titles, Mighty God, definitely indicates it. This title, written in the Hebrew as El, may also be translated as God or God-like One and may have the meaning of mighty men or an angel. But in Isaiah 9:6-7 and 10:20-21, which are millennium passages, there is no question that it means God, or the One True God, or Yahweh.
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.
7 There will be no end to the increase of His government or of peace,
On the throne of David and over his kingdom,
To establish it and to uphold it with justice and righteousness
From then on and forevermore.
The zeal of the Lord of hosts will accomplish this.
Now it will come about in that day that the remnant of Israel, and those of the house of Jacob who have escaped, will never again rely on the one who struck them, but will truly rely on the Lord, the Holy One of Israel.
21 A remnant will return, the remnant of Jacob, to the mighty God.
There are also a few verses in the New Testament that undoubtedly declare Christ as God, and reflect this Old Testament title of “Mighty God.” In John 1:1 it is clearly written that the Word, which is Christ, “was God.” In Colossians 2:9 we read that “in Him [Christ] dwells all the fullness of the Godhead bodily.” In 1 John 5:20 John clearly identifies Jesus Christ as “Son of God,” and also as “the true God and eternal life.” Hebrews 1:8-9 is particularly noteworthy, for in these verses the declaration of Christ’s deity is by the words of His Father.
But of the Son He says,
“Thy throne, O God, is forever and ever,
And the righteous scepter is the scepter of His kingdom.
9 “Thou hast loved righteousness and hated lawlessness;
Therefore God, Thy God, hath anointed Thee
With the oil of gladness above Thy companions.”