The Son the Radiance

Heb 1:3 The Son is the radiance of God's glory and the exact representation of his being, sustaining all things by his powerful word. After he had provided purification for sins, he sat down at the right hand of the Majesty in heaven.

As the light that comes from the sun is the radiance of the sun, so Jesus is the radiance of God. And just as we see the light that comes from the sun and call that "the sun", so also when we see Jesus we see the Father. Jesus said, "Anyone who has seen me has seen the Father." John 14:9 For "No one has ever seen God, but God the One and Only, who is at the Father's side, has made him known." John 1:18 How are all things sustained? It is by the powerful word of Jesus Christ, the Son of God that all things are sustained. Understand that this is heresy to the Muslim and Jew. Yet these facts about the person of Christ are central to the gospel.

As for his work on earth, Christ died for sins. "Now, brothers, I want to remind you of the gospel I preached to you, which you received and on which you have taken your stand.  By this gospel you are saved, if you hold firmly to the word I preached to you. Otherwise, you have believed in vain. For what I received I passed on to you as of first importance: that Christ died for our sins according to the Scriptures ..." 1Cor 15:1-4 "He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world." 1John 2:2

Being seated indicates his work is finished and his throne established.

The Berean Christian Bible Study Resources