Matthew 25:31

But when the Son of man shall come in his glory, and all the angels with him, then shall he sit on the throne of his glory.

As the poet John Milton expressed it:

The aged earth aghast With terror of that blast Shall from the surface to the center shake, When, at the world's last session, The dreadful Judge in middle air shall spread His throne.[10]

This place does not teach that Christ will sit upon the throne of his glory only upon the occasion of his second coming, nor that he will only then begin to do so. He had already revealed to his disciples that he would sit on his glorious throne "in the times of the regeneration" (Matthew 19:28), that is, in the times of the new birth, namely, now, in this present era, during which period the twelve apostles are also reigning with him on twelve thrones; ruling over the twelve tribes of spiritual Israel, which is the church. The expression, "then" shall he sit, etc., refers to a special sitting for the great assize, the judgment of the great day. He is already upon the throne of his glory; but then he will be visibly so, and every eye shall see him, and they shall look upon him whom they pierced. His angels even now are diligent in the service of them that shall be the heirs of everlasting life (Hebrews 1:14), but THEN shall they APPEAR! Now Christ, from his glory throne, intercedes for his own; but THEN he shall APPEAR in judgment (see 2 Thessalonians 1:8).