A message [sermon] that merely advocates morality and compassion remains sub-Christian even if the preacher can prove that the Bible demands such behaviors. By ignoring the sinfulness of humankind, which makes even our best works tainted before God (Isa. 64.6; Luke 17.10), and by neglecting the grace of God, which make obedience possible and acceptable (1 Cor. 15.10; Eph. 2.8-9), such messages necessarily subvert the Christian message. Christian preachers often do not recognize this counter-gospel impact of their preaching because they are simply recounting a behavior clearly specified in the portion of the text in front of them. But a message that even inadvertently teaches others that their works merit God’s acceptance inevitably leads people away from the Gospel. By themselves, moral axioms and advocacy of ethical conduct fall short of the requirements of biblical preaching.
Brian Chapell, Christ-centered Preaching (Grand Rapids; Baker Academic, 2005), 220.