"The cross of Christ is the heart of the apostles’ gospel and of their piety and praise as well; so surely it ought to be central in our own proclamation, catechesis, and devotional practice? True Christ-centeredness is, and ever must be, cross-centeredness. The cross on which the divine-human mediator hung, and from which he rose to reign on the basis and in the power of his atoning death, must become the vantage point from which we survey the whole of human history and human life, the reference point for explaining all that has gone wrong in the world everywhere and all that God has done and will do to put it right, and the center point for fixing the flow of doxology and devotion from our hearts.
"Healthy, virile, competent Christianity depends on clear-headedness about the cross; otherwise we are always off-key. And clear-headedness about the cross, banishing blurriness of mind, is only attained by facing up to the reality of Christ’s blood-sacrifice of himself in penal substitution for those whom the Father had given him to redeem.
"Why then is it that in today's churches, even in some professedly evangelical congregations, this emphasis is rare? Why is it that in seminary classrooms, professional theological guilds, Bible teaching conferences, and regular Sunday preaching, not to mention the devotional books that we write for each other, so little comparatively is said about the heart-stirring, life-transforming reality of penal substitution? Several reasons spring to mind.
"First, we forget that the necessity of retribution for sin is an integral expression of the holiness of God, and we sentimentalize his love by thinking and speaking of it without relating it to this necessity. This leaves us with a Christ who certainly embodies divine wisdom and goodwill, who certainly has blazed a trail for us through death into life, and who through the Spirit certainly stands by each of us as friend and helper (all true, so far as it goes), but who is not, strictly speaking, a redeemer and an atoning sacrifice for us at all.
"Second, in this age that studies human behavior and psychology with such sustained intensity, knowledge of our sins and sinfulness as seen by God has faded, being overlaid by techniques and routines for self-improvement in terms of society's current ideals of decency and worthwhileness of life. It is all very secular, even when sponsored by churches, as it often is, and it keeps us from awareness of our own deep guilty and shameful alienation from God, which only the Savior, who in his sinlessness literally bore the penalty of our sins in our place, can deal with.
"Third, in an age in which historic Christianity in the West is under heavy pressure and is marginalized in our post-Christian communities, we are preoccupied with apologetic battles, doctrinal and ethical, all along the interface of Christian faith and secularity—battles in which we are for the most part forced to play black, responding to the opening gambits of our secular critics. Constant concern to fight and win these battles diverts our attention from thorough study of the central realities of our own faith, of which the atonement is one.
"Fourth, heavyweight scholars in our own ranks, as we have seen, line up from time to time with liberal theologians to offer revisionist, under-exegeted accounts of Bible teaching on the atonement, accounts which in the name of Scripture (!) play down or reject entirely the reality of penal substitution as we have been expounding it. The effect is that whereas from the sixteenth to the nineteenth century evangelicals stood solid for penal substitution against unitarianism (Socinianism) and deism, and taught this truth as no less central to the gospel than the incarnation itself, today it is often seen as a disputed and disputable option that we can get on quite well without, as many already are apparently doing.What in the way of understanding our Savior and our salvation we lose, however, if we slip away from penal substitution, is, we think, incalculable."
Taken from "In My Place Condemned He Stood" by J.I. Packer and Mark Dever, pp. 150-151, © 2008, Crossway Books