“Be” messages full only of moral instruction imply that we are able to change our fallen condition in our own strength. Such sermons communicate (although usually unintentionally) that we clear the path to grace and that our works earn and/or secure our acceptance with God. However well intended, these sermons present a faith indistinguishable from that of morally conscientious Unitarians, Buddhists, or Hindus. . . .
The fundamental biblical truth that differentiates the gospel from a morality lesson is the assertion that our works always remain tainted by our humanity. Of themselves our actions can never earn God’s blessing or secure his favor (Isa. 64:6; Luke 17:10). Although there are blessed consequences to heeding divine commands designed for our good, mere conformity to biblical commands offers no heavenly merit. If we had to earn grace prior to, or after, our salvation it would not be grace that we gained.
There are many “be” messages in Scripture, but they always reside in a redemptive context. Since we cannot be anything that God would approve apart from his sanctifying power, the source of that grace must permeate any exhortation for biblical behavior. “Be” messages are not wrong in themselves; they are wrong messages by themselves. People cannot do or be what God requires without the work of Christ in, for, and through them. Simply railing at error and hammering at piety may convince others of their inadequacy or callous them into self-sufficiency, but these messages also keep true godliness remote. Thus, instruction in biblical behavior barren of redemptive truth only wounds, and though it is offered as an antidote to sin such preaching either promotes pharisaism or prompts despair. Christ-centered preachers accept neither alternative. . . . The holy standards that pierce the heart whenever people recognize the depth of their divine obligations become salve to their souls when we preach their fulfillment in Christ and their enablement by His Spirit. . . .
When we exhort congregations to stand for God against the assaults of Satan we must never forget the balance of the Pauline imperative: “Finally, brethren, be strong in the Lord and in the power of his might” (Eph 6:10, KJV). Amidst his most strident “be” message, the apostle remained Christ-focused. Today’s preacher has no lesser task.
Faithful expository preaching unfolds every text in the context of its redemptive import. The success of this endeavor can be assessed by a bottom-line question every preacher should ask at the end of each sermon: When my listeners walk out the doors of this sanctuary to perform God’s will, with whom do they walk? If they march to battle the world, the flesh, and the devil with only me, myself, and I, then each parades to despair. However, if the sermon has led all persons within sight of the Savior and they now walk into their world with his aid firmly in their grasp, then hope and victory brighten the horizon. Whether people depart alone or in the Savior’s hand will mark the difference between futility and faith, legalism and true obedience, do-goodism and real godliness.
Bryan Chapell, Christ-Centered Preaching: Redeeming the Expository Sermon, Baker, 1994, p. 284-286.