While our Savior Christ, both above and below, indicates His ascent into the heavens and says that Peter will not follow Him now, yet will follow afterward, evidently after the completion of his apostolic ministry, when the proper time comes for the calling of the saints into the City above, Peter promises to be ready even to undergo death.
It is as though he is going by another path and proceeding without being guided by the direct meaning of Christ's words. I think he says this because he did not understand precisely the meaning of these words.
Perhaps he thinks that the Lord will go either to villages more savage than those of the Jews, or even to other nations. Hearing His preaching, they may be so hardened against His words that the boldness of the other Jews will appear altogether insignificant, and the fury proper to the Pharisees will seem entirely mild.
For this reason he promises to follow Him unswervingly, not only to die, but, if necessary, to die without any hesitation.
Something similar to this occurred earlier, and I shall mention it again. Once, when Christ withdrew from the madness of the Jews, from their unrestrained rage and unbridled tongue, He began to walk through the regions of Galilee. By His miracles He stirred up great wonder at Himself among them.
When the brother of Mary and Martha, I mean Lazarus, died, He again knew it as God. Then He said to the disciples: "Lazarus, our friend, has fallen asleep; but I go that I may awaken him" (Jn 11:11).
To this the disciples, out of love for Him, said to Him: "The Jews were just now seeking to stone You, and are You going there again?" (Jn 11:8). When the Lord insisted and commanded that they return to the land of the Jews, "Thomas, who is called the Twin, said to the other fellow disciples: Let us also go, that we may die with Him" (Jn 11:16).
I think Peter's words contain the same purpose. Perhaps he thinks, as I have said before, that Christ will go somewhere to preach and will there be in danger.
Therefore Peter himself, bound to Him by inseparable love, promises to show an invincible and unshakable eagerness for this. He says that nothing at all remains that has power to hinder him, since he has already resolved to follow, even if death for the Teacher awaits him.