Why the next words: “and is seated at the right hand of God”?

Because Christ ascended to heaven to show there that he is head of his church, the one through whom the Father rules all things.

How does this glory of Christ our head benefit us?

First, through his Holy Spirit he pours out gifts from heaven upon us his members.

Second, by his power he defends us and keeps us safe from all enemies.

How does Christ’s return “to judge the living and the dead” comfort you?

In all distress and persecution, with uplifted head, I confidently await the very judge who has already offered himself to the judgment of God in my place and removed the whole curse from me. Christ will cast all his enemies and mine into everlasting condemnation, but will take me and all his chosen ones to himself into the joy and glory of heaven.

Finally we believe, according to God’s Word, that when the time appointed by the Lord is come (which is unknown to all creatures) and the number of the elect is complete, our Lord Jesus Christ will come from heaven, bodily and visibly, as he ascended, with great glory and majesty, to declare himself the judge of the living and the dead. He will burn this old world, in fire and flame, in order to cleanse it.

Then all human creatures will appear in person before the great judge—men, women, and children, who have lived from the beginning until the end of the world. They will be summoned there “with the archangel’s call and with the sound of God’s trumpet.” For all those who died before that time will be raised from the earth, their spirits being joined and united with their own bodies in which they lived.

And as for those who are still alive, they will not die like the others but will be changed “in the twinkling of an eye” from perishable to imperishable.  Then the books (that is, the consciences) will be opened, and the dead will be judged according to the things they did in the world, whether good or evil.  Indeed, all people will give account of all the idle words they have spoken, which the world regards as only playing games.
And then the secrets and hypocrisies of all people will be publicly uncovered in the sight of all.

Therefore, with good reason the thought of this judgment is horrible and dreadful to wicked and evil people. But it is very pleasant and a great comfort to the righteous and elect, since their total redemption will then be accomplished.  They will then receive the fruits of their labor and of the trouble they have suffered; their innocence will be openly recognized by all; and they will see the terrible vengeance that God will bring on the evil ones who tyrannized, oppressed, and tormented them in this world. The evil ones will be convicted by the witness of their own consciences, and shall be made immortal— but only to be tormented in “the eternal fire prepared for the devil and his angels.”

In contrast, the faithful and elect will be crowned with glory and honor. The Son of God will profess their names before God his Father and the holy and elect angels; all tears will be wiped from their eyes; and their cause— at present condemned as heretical and evil by many judges and civil officers—will be acknowledged as the cause of the Son of God. And as a gracious reward the Lord will make them possess a glory such as the human heart could never imagine. So we look forward to that great day with longing in order to enjoy fully the promises of God in Christ Jesus, our Lord.