Theologians refer to something called the “penal substitutionary theory of atonement” (PSA), which is a complicated way of trying to explain that Christ died in the place of sinners, taking on himself the full sentence we deserved in order to fully satisfy God with respect to sin. PSA is the traditional way of understanding one aspect of what the Lord Jesus was doing on the cross.
A number of people have proposed alternative theories of atonement — offering, in effect, substitutes for substitution — primarily because they dislike the idea of an angry God displaying his wrath against sin.
