Should we preach about Jesus in His earthly ministry or after the cross?
Preaching should focus on Christ after the cross—His death, burial, resurrection, and ascension—not on Jesus in His earthly ministry of miracles, signs, and wonders. Paul says henceforth we know no man after the flesh; the pre-cross Christ was not the object of salvation as the post-cross Christ is, because the cross makes salvation possible.
Les explains that Paul's "wherefore" is tied to the work of the cross—His death, burial, and resurrection. From that point on, Paul says, "we know no man after the flesh." Les points out that much preaching today is about Jesus in His earthly ministry: His miracles, signs, and wonders, Sunday after Sunday. But Paul says we are not following any man in the flesh. We are to take Christ after the work of the cross, after His death, burial, and resurrection, now ascended in glory. That is the Christ we are attached to. Les grants it is the same man and the same God, but the Christ before the cross was not the object of salvation that He is after the cross, because it is the work of the cross that makes possible our salvation experience. Paul lived contemporary with Christ and had known Him after the flesh, but henceforth, from His death, burial, and resurrection, we do not look back and know Him in His earthly ministry as such.