I don’t know what’s worse: saying you understand the mind of God or not even bothering to try. In this Sunday’s second reading (rom 11:33-36), Paul tells the Romans: “How inscrutable are [God’s] judgments and how unsearchable his ways! For who has known the mind of the Lord or who has been his counselor?”

Some of the world’s worst evils come from people who commit those evils while professing to act as God’s agent. Take the recent beheading of American journalist James Foley by a member of the terrorist group ISIS, for example. Aside from their stated revenge in response to America’s recent military moves against them, a jihadist website states thatIslamic law mandates death for heretics and apostates. This group uses that rationale to kill foreigners as well as Muslims who condemn the ways of ISIS. ISIS quotes the Qur’an: “When you meet the unbelievers, strike the necks.”   This Jihadist website then justifies Foley’s murder: “James Foley was certainly an unbeliever, and one from a state with which the Islamic State considers itself to be at war — thus they did not consider him innocent.”

War was responsible for the plight of Jerusalem as described in Sunday’s first reading from Isaiah (is 22:19-23). Jerusalem revolted against Assyria and our reading begins with the aftermath and Isaiah’s dressing down of Shebna, “master of the palace.” Speaking in the Lord’s name, Isaiah says:

“I will summon my servant Eliakim, son of Hilkiah; … I will give over to him your authority. He shall be a father to the inhabitants of Jerusalem, and to the house of Judah.”

Apparently Shebna put his faith in military forces, alliances with other nations and politics to save Jerusalem, not in the Lord. Eliakim is more of a Christ-like figure, whom Isaiah calls God’s servant—just as Christ was God’s servant.

It was servanthood that Jesus preached, as well as humility and love—not war and revenge. That’s why when he saw his disciples argue among themselves about who should take the seat of power next to Jesus, the Master tells them that the greatest among them will be the ones who act as servants—washing feat, binding wounds, feeding the hungry and preaching the word of God.

And the word of God, although it comes from the inscrutable mind of God, is really very simple: Love your Lord and love your neighbor. Everything else is from the evil one. Our gospel reading (mt 16:13-20) demonstrates Christ’s love for simplicity with his naming of Peter—the simplest of his disciples—as his Church’s foundation. Peter, like Eliakim, was given the key to God’s kingdom because he knew its purpose: to give God’s children access to truth and life. Jesus knew Peter wouldn’t corrupt God’s gifts with any of his own spin and sin.

The only good coming out of all that evil ISIS is committing is the reminder that absolute evil DOES exist. Let’s not repeat Shebna’s mistake and believe in our own ability to defeat it. Prayer is our key to the mind of God. Let’s use it. It’s our most powerful weapon.