“If anyone would come after Me, let him deny himself, take up his cross, and follow me.” Mark 8 
Tradition holds that Peter was put to death by crucifixion, but that he pleaded that he would be crucified in a way that was unlike Jesus’ crucifixion. He wanted to be crucified head down. In 1600, Michelangelo Merisi da Caravaggio (just Caravaggio to his friends), was engaged to paint a representation of what that scene might have looked like. You can view the art here: https://en.wikipedia.org/wiki/Crucifixion_of_Saint_Peter_(Caravaggio)#/media/File:Crucifixion_of_Saint_Peter-Caravaggio_(c.1600).jpg
As you look at the painting, you are struck almost immediately by the awkwardness of the scene. Romans knew crucifixion. The Jewish historian Josephus cites a Roman general from 4 B.C., around the time of Jesus’ birth and childhood, who claimed that at that point there had already been 2,000 Jews crucified at Roman hands. Other accounts show a sort of macabre artistry to the Roman method of execution, an understanding of efficiency and pain that it had in terms of capital punishment. But Peter wanted to be crucified upside down. This wasn’t the usual way. This was something different.
The three men who are hoisting Peter’s cross up seem to be doing so with great trouble. The usual way of doing things isn’t working here. To complicate matters, Peter, the aged but still strong fisherman seems to be straining against the cross to look at something out of the frame of the picture (in terms of the chapel the painting was produced for, he is either looking across the aisle at Paul or over to the mother of Jesus). There is a real feel that this is something different and strange, something upside down.
Which is perhaps something for us to reflect upon this Lent. When Christ calls us to follow Him, He rarely calls us into the familiar. This is likely not because Jesus likes to terrify us with things that are different just for the sake of their difference. Rather, Jesus knows what we find familiar. We find our sins familiar. We find our pride familiar. We find our sloth familiar. Jesus calls us out of those familiarities to our crosses, which appear to us to be upside down approaches to life.
And in those upside down approaches to life, we find the Gospel. We find that our crosses are so different from His Cross. We find that we are not worthy of His Cross, just as Peter confessed with his upside down cross. He suffered beyond the suffering of those 2,000 Jews, of St. Peter, of all those who have ever been crucified. Because in His Cross, He suffered for the entire world. His Cross stands as a noble sign to all of humanity of God’s grace, and our crosses, like Peters, stand as awkward testimonies to how different we are from Him. And that is the Gospel. Because His Cross did what ours could never do. Thanks be to God.