I read this fascinating anecdote in D. A. Carson's The Cross and Christian Ministry (p. 63):
I have heard a Mennonite leader assess his own movement in this way. One generation of Mennonites cherished the gospel and believed that the entailment of the gospel lay in certain social and political commitments. The next generation assumed the gospel and emphasized the social and political commitments. The present generation identifies itself with the social and political commitments, while the gospel is variously confessed or disowned; it no longer lies at the heart of the belief system of some who call themselves Mennonites.
Dr. Carson then makes the observation, Whether or not this is a fair reading of the Mennonites, it is certainly a salutary warning for evangelicals at large. We are already at the stage where many evangelical leaders simply assume the message of the cross, but no longer lay much emphasis on it. I want to keep quoting but I'll leave off and you can pursue it for yourself if you want.
In other words, we are never more than two generations away from losing the gospel. Some would say one, but it is perceptive to note that we don't go straight from cherishing to ignoring, but from cherishing to assuming to ignoring. Somehow, our cherishing of the gospel unto cultural engagement slowly begins to skip the gospel to get to the cultural engagement. I am thankful to be studying at a seminary where these two are not divorced.
C. J. Mahaney's Living the Cross-Centered Life is just the kind of accessible book that will help us everyday people avoid fatal gospel-assumption.