(RNS) Conservative talk show host Glenn Beck is promising to air a week-long report probing the past of progressive evangelical leader Jim Wallis.

“I can do a whole week — and we will — on you with your spread the wealth, social justice nonsense,” Beck said of Wallis on his FOX News television show on Wednesday (March 17).

The two men have verbally dueled since Beck said earlier this month that Christians should leave congregations that espouse social justice. Wallis, in turn, suggested Christians should stop watching Beck’s program.

Beck compared Wallis’ “Marxist” views to those espoused by President Obama’s former pastor, Rev. Jeremiah Wright. Obama broke ties with Wright in 2008 over his controversial comments.

“I think you are really like Jeremiah Wright on sedatives,” Beck said.

Wallis, an author and longtime friend of Obama, responded on the Web site of his Sojourners ministry by defending social justice.

“It’s isn’t `Marxist,’ but is central to the gospel teachings of Jesus and at the heart of biblical faith,” wrote Wallis, who just completed a one-year term on Obama’s Advisory Council on Faith-based and Neighborhood Partnerships.

Beck said his staff has been working for eight weeks investigating Wallis and vowed that “when the hammer comes, it’s going to be hammering hard and all through the night.”