Dorothy L. Sayers wrote a seminal essay—“Creed or Chaos?”—that later become a lead chapter in her book with the same title (1949). A subsequent edition (1995) carries the subtitle: “Why Christians Must Choose Either Dogma or Disaster; Or, Why It Really Does Matter What You Believe.” While appreciating Sayers’s basic concern for preserving historic Christian orthodoxy, this paper examines the arguments for five overlapping theses that would significantly complicate her basic claims. 1) Churches often change far more rapidly and radically than their leaders or constituencies would like to admit. 2) Those persons aggressively calling for fidelity to biblical or historical positions with respect to Church doctrines or Christian lifestyles are frequently among the chief catalysts for those changes, including some of the most dramatic ones. 3) Cultural encounters and influences also play an enormous role in those changes, whether the pervasive effects of surrounding societies (local, national, or now also media driven) or the impact of encounters with alien or foreign cultures brought about by aggressive evangelism, discipleship, church planting, or other missionary outreaches. 4) Beliefs are deeply intertwined with behaviors, so that the claim from some in the Anabaptist, Pietist, and Holiness movements that orthodoxy cannot be separated from orthopraxy seems to be true on a pragmatic level, given what we can learn from the psychology and sociology of religion. 5) Changes may go in many directions on different levels, so that the familiar evangelical concerns that changes inevitably tend toward theological liberalism or secular unbelief are simply wrong—some of the most striking changes are neither liberal nor secular, though they may be decidedly unbiblical and fly in the face of the Nicene Creed. Specific examples to support these five theses will be drawn from a variety of Christian traditions, with special attention to evangelical bodies, including a focused case study running throughout that references the Missionary Church, a relatively small evangelical denomination with a tangled ecclesial heritage drawing on five distinct but intersecting Protestant identities. There will also be repeated allusions to the ironies of unintended consequences, a frequent result of trying to promote truth while guarding against change. This ironical pattern of unexpected results is so pervasive that it might merit a separate paper.