What Did the Cross Achieve?

A Classic Essay on Penal Substitutionary Atonement from Theologian J. I. Packer

Penal substitutionary atonement—the belief that Jesus's death on the cross satisfied God's wrath against sin—is central to the Christian faith, but frequently debated.  Is it just to punish an innocent person in place of the guilty? How can the temporary death of one substitute for the eternal...