Rev. 3:21 He who conquers, I will grant him to sit with me on my throne, as I Myself have conquered and taken My seat with My Father on His throne. He who has an ear, let him hear what the Spirit says to the churches.
St. Andrew of Caesarea ca. 563-637
The Kingdom and the repose of the future age are indicated by the throne. Therefore He says that “those who have conquered the enemy will be co-glorified” (Rom. 8:17) with Me and will “co-reign” (2 Tim. 2:12). The as I Myself conquered is said in human terms to refer to the assumption [of the flesh]. For God the Logos did not acquire the Kingdom as a reward for virtue, for this He possesses eternally as part of His essence. For if this were not the case, He would not have been able to share it [the Kingdom] with others; but according to the Theologian and “Son of Thunder,” (Mk. 3:17) He has imparted this to all the saints from How own fullness (cf. Jn. 1:16). Therefore He has promised the Holy Apostles that they will “sit on twelve thrones to judge the twelve tribes of Israel” (Mt. 19:28; Lk. 22:30) of the future. Since He became human for our sake, being God and King before the ages, He had partaken of everything that is our own except sin (cf. Heb. 4:15), and imparted all that is His to those victorious over the devil, as much as possible for people to receive. Therefore, having made the cloud a vehicle for the rise heavenward of His Ascension (Acts 1:9), He also says through the Apostle that the saints will be “caught up in the clouds to meet Him (1 Thess. 4:17), and He will come [as] Judge, as Creator and Master of creation, handing over to the saints to judge those who opposed the truly divine and blessed slavery, as the Apostle says, “Do you not know that we will judge angels?” (1 Cor. 6:3) that is, the “rulers of darkness” (Eph. 6:12). Since we have such a lover of humanity as Judge, let us hurry to gain His favor, fulfilling endlessly Solomon’s saying “At all times my garments have been white,” (Eccl. 9:8) not being stained by evil deeds. For this way, having decorated our beloved souls as for a wedding (cf. Mt. 22:11-12), we will present to the King for a union, and we will gain eternal blessings in Him, Christ our God, the Supplier of these, to Who is due glory, honor, worship with the Father, together with the Holy Spirit, unto the ages of ages. Amen. (Commentary on the Apocalypse)