During a time of mounting challenge for the U.S. Catholic hierarchy, Pope Benedict XVI appointed a new Church leader for Philadelphia: Archbishop Charles Chaput of Denver. He’s a trailblazer with a knack for advancing the claims of faith in the public square, explaining inconvenient truths to pro-choice politicians, and reinvigorating the religious identity of Church institutions.

Some leaders of Catholic universities and social agencies see their religious legacy as a threat to greater government subsidies or secular prestige. The archbishop contends that if our outreach isn’t deeply Christ-centered, we shouldn’t call it “Catholic.” He’s also prepared to cross swords with self-identified “Catholic” politicians who advance abortion rights and same-sex “marriage.”

In his bestselling work Render Unto Caesar: Serving the Nation by Living Our Catholic Beliefs in Political Life, the archbishop critiqued John F. Kennedy’s pledge to separate his political decisions from his faith. The pledge shielded him from the unjust attacks of anti-Catholic bigots, but it also introduced an alien “secularist” approach to the conduct of American politics that has contributed to the privatization of religious faith.

Like Pope Benedict, who has anticipated a future role for religious believers as a “creative minority” — a leaven in the West’s increasingly secular culture — the archbishop argues that religious witness plays an essential role: The faithful defend and transmit fundamental truths that transcend man-made laws and government. Accordingly, this witness secures freedom, by limiting the reach and authority of the state.

At present, Catholics in Philadelphia, still reeling from a fresh clergy-abuse scandal, are looking for gifted pastor who can address the problems that have damaged the local Church’s credibility. Archbishop Chaput’s record in Denver suggests he will be equal to the task.

A firm defender of the Dallas Charter’s plicy of “zero tolerance” for clergy who have been credibility accused of abuse, he has shown himself to be a careful steward of the Church’s resources, successfully blocking a recent legislative effort to lift the statute of limitations for civil suits against the Church — but not for other groups.

Over the long haul, however, the new archbishop of Philadelphia will make his mark as a leader of the New Evangelization who is prepared to challenge the received wisdom of secular elites.

“Christianity is not mainly — or even significantly — about politics. It’s about living and sharing the love of God. And Christian political engagement, when it happens, is never mainly the task of the clergy. That work belongs to lay believers who live most intensely in the world,” he said, during a recent speech before a Baptist audience in Texas. “But a Christian life begins in a relationship with Jesus Christ, and it bears fruit in the justice, mercy and love we show to others because of that relationship.”