What does God ask us to do concerning the work of the cross?
Concerning the work of the cross, God asks us simply to believe it. The work of the cross is the bedrock of salvation, and though it is beyond human comprehension, it is simple enough that all God requires is belief. The world, however, refuses to believe.
Les explains that the work of the cross is the very bedrock of our salvation. He notes that it is so simple that people stumble over it, yet so complex that even a thousand years of life could not comprehend it. Humans cannot comprehend the power of the work of the cross; it is beyond us. But God's requirement is simple: all He asks us to do is believe it. The world, however, refuses to do so. The context also references Galatians, where He gave Himself for our sins to deliver us from this present evil world.