On the third day He rose again from the dead. He ascended into heaven and is seated at the right hand of God, the Almighty Father. From there He will come to judge the living and the dead.
By His resurrection we have the unshakeable assurance of obtaining victory over the rule of death. The fact is that He could not be held prisoner by death’s chains. By exercising all His power He came out of it, thus breaking in pieces its weapons in such a way that they can no longer strike us mortally.
His resurrection, then, is the certain fact, the basis and foundation not only of our own resurrection to come, but also of this present resurrection which enables us to live a new sort of life.
By His ascension into heaven He has opened to us the gate of the kingdom of heaven which was closed to everyone in Adam. In fact He has entered into heaven with our human nature, in our name as it were, so that in Him we already posses heaven through hope and sit with Him in the heavenly realms. And it is for our good that He has entered into God’s sanctuary — a sanctuary not made by man’s hand. In accordance with His office of eternal priest He has entered there to be our perpetual advocate and mediator.
He is seated at the right hand of the Father. This means, first of all, that He is established, and declared to be, King, Master and Lord over all things in order to keep and sustain us by His power, so that His reign and glory might be our strength, power and glory against the powers of hell.
Secondly, this means that He received all the graces of the Holy Spirit in order to distribute them to those who are faithful to Him, and to enrich them with them. Hence, although His body has been taken up to heaven and is no longer here for us to see, yet He does not cease to support His faithful ones with His help and power, and to show to them the evident force of His presence, according to His promise, “See, I am with you every day until the end of the world.” (Matthew 28:20)
It follows, finally, that He will descend from there on the last day. He will do this visibly, just as He was seen to ascend. He will then appear to all in the incomprehensible majesty of His reign in order to judge the living and the dead, (that is to say those whom that day will find still alive, and those who will then be already dead). He will render to all according to their works, just as each one, by his works, will have shown himself to be faithful or unfaithful. It is an extraordinary comfort to us to know that the judgment is committed to the very one whose coming means, for us, nothing but salvation.
John Calvin, Truth For All Time, pp. 41-43