by John Calvin
From [Christ's ascension] our faith receives many benefits.
First it understands that the Lord by his ascent to heaven opened the way into the Heavenly Kingdom, which had been closed through Adam [John 14:3]. Since he entered heaven in our flesh, as if in our name, it follows, as the apostle says, that in a sense we already "sit with God in the heavenly places in him" [Eph. 2:6], so that we do not await heaven with a bare hope, but in our Head already possess it.
Secondly, as faith recognizes, it is to our great benefit that Christ resides with the Father. For, having entered a sanctuary not made with hands, he appears before the Father's face as our constant advocate and intercessor [Heb. 7:25; 9:11–12; Rom. 8:34]. Thus he turns the Father's eyes to his own righteousness to avert his gaze from our sins. He so reconciles the Father's heart to us that by his intercession he prepares a way and access for us to the Father's throne. He fills with grace and kindness the throne that for miserable sinners would otherwise have been filled with dread.
Thirdly, faith comprehends his might, in which reposes our strength, power, wealth, and glorying against hell. "When he ascended into heaven he led a captivity captive" [Eph. 4:8, cf. Vg.; cf. Ps. 68:18], and despoiling his enemies, he enriched his own people, and daily lavishes spiritual riches upon them. He therefore sits on high, transfusing us with his power, that he may quicken us to spiritual life, sanctify us by his Spirit, adorn his church with divers gifts of his grace, keep it safe from all harm by his protection, restrain the raging enemies of his cross and of our salvation by the strength of his hand, and finally hold all power in heaven and on earth. All this he does until he shall lay low all his enemies [1 Cor. 15:25; cf. Ps. 110:1] (who are our enemies too) and complete the building of his church. This is the true state of his Kingdom; this is the power that the Father has conferred upon him, until, in coming to judge the living and the dead, he accomplishes his final act.
From Institutes of the Christian Religion by John Calvin