Sunday, Sept. 16, is the 24th Sunday of Ordinary Time (Year B). Mass Readings: Isaiah 50:5-9, Psalm 116:1-6, 8-9, James 2:14-18, Mark 8:27-35.

We’ve all seen those bracelets that ask, “What would Jesus do?” This question can be a helpful reminder of our need to use Jesus as a reference point and to follow the example of Our Lord. That’s the theme of Thomas à Kempis’ spiritual classic The Imitation of Christ.

It’s also a welcome point of agreement with our separated brethren. In fact, “What would Jesus do?” has been particularly popular in the Protestant community, initially being popularized by the 19th-century Baptist preacher Charles Spurgeon and the Congregationalist author Charles Sheldon and his novel In His Steps.

Though the subject of faith and works has long been contentious between Catholics and Protestants, both recognize — with St. James — the need to put faith into practice: “What good is it, my brothers and sisters, if someone says he has faith but does not have works.” “Faith of itself, if it does not have works, is dead.”

While “What would Jesus do?” is an important question to ask, it comes with a huge caveat. There’s a well-known saying in biblical studies: “By their Lives of Christ ye shall know them.” What this means is that scholars tend to write biographies of Jesus that essentially remake him in the image that the author prefers. Marxist scholars envision a Marxist Jesus; politically conservative scholars see a politically conservative Jesus, etc.

There’s an example of just that phenomenon in this Sunday’s Gospel reading. When Jesus declares that he will be rejected by the authorities, killed and rise on the third day, “Peter took him aside and began to rebuke him.” The prince of the apostles couldn’t imagine such things happening to Jesus — who Peter had just, correctly, identified as God’s long-awaited Messiah. The Life of Christ that Peter was envisioning would have had an entirely different ending!

Peter must have been shocked when Jesus, in full view of the other disciples, rebuked him in turn, saying, “Get behind me, Satan. You are thinking not as God does, but as human beings do.” Indeed, Jesus was determined to perform a different mission than Peter and others had in mind for him. Rather than being a political deliverer who would expel the hated Romans from Israel, he would fulfill the prophecy of Isaiah: “I gave my back to those who beat me, my cheeks to those who plucked my beard; my face I did not shield from buffets and spitting.”

And yet Jesus would also emerge from the grave, fulfilling the prophecy of the Psalms: “For he has freed my soul from death, my eyes from tears, my feet from stumbling. I shall walk before the Lord in the land of the living.”

None of this was imaginable to Peter or his fellow disciples, and it reveals to us that — when we ask the question, “What would Jesus do?” — we need to ask follow-up questions: “How sure am I that I really understand what Jesus would do? Am I recasting him in my own image, just rationalizing what I want to do? Am I thinking like men rather than God?”

Jimmy Akin is the senior apologist at Catholic Answers,

a contributing editor to Catholic Answers Magazine

and a weekly guest on Catholic Answers Live. He blogs at NCRegister.com.