If the title's proposition is true, then why would there be ringing in the pulpits devoid of the declaration of the person and work of Christ? If the Christian life is held afloat by the gratitude that is formed by the realization in heart and mind of what Christ is for us, then why do bare platitudes and niceties blare from the mouths of those who supposedly are Christ's mouthpieces?
No preaching is true, biblical preaching unless it is redemptive-historical. Christ Himself testifies, "You search the Scriptures because you think that in them you have eternal life; and it is they that bear witness about me" (John 5:39). Preachers who have a penchant for serving "10 steps to this" or "being a better that" think they are preaching life, but the Law kills. "Do this and do that" preaching is Law-preaching. Indeed, the Law must be declared from the pulpits, but apart from an ensuing proclamation of Christ in the Gospel, the Law will only be capable of doing one thing: bring despair. Why? Because God demands perfect obedience to the Law.
But how can the Law be made lovely? Only by the knowledge that Christ has perfectly obeyed the Law and paid its penalty in our stead, and that grateful for this, the Law becomes our guide for expressing this gratitude through its obedience.
Calvin says it best:
"When we see that the whole sum of our salvation, and every single part of it, are comprehended in Christ, we must beware of deriving even the minutest portion of it from any other quarter. If we seek salvation, we are taught by the very name of Jesus that he possesses it; if we seek any other gifts of the Spirit, we shall find them in his unction; strength in his government; purity in his conception; indulgence in his nativity, in which he was made like us in all respects, in order that he might learn to sympathise with us: if we seek redemption, we shall find it in his passion; acquittal in his condemnation; remission of the curse in his cross; satisfaction in his sacrifice; purification in his blood; reconciliation in his descent to hell; mortification of the flesh in his sepulchre; newness of life in his resurrection; immortality also in his resurrection; the inheritance of a celestial kingdom in his entrance into heaven; protection, security, and the abundant supply of all blessings, in his kingdom; secure anticipation of judgement in the power of judging committed to him. In fine, since in him all kinds of blessings are treasured up, let us draw a full supply from him, and none from any other quarter. Those who, not satisfied with him alone, entertain various hopes from others, though they may continue to look to him chiefly, deviate from the right path by the simple fact, that some portion of their thought takes a different direction. No distrust of this description can arise when once the abundance of his blessings is properly known." (Institutes 2.16.19)