"Cheap grace is the preaching of forgiveness without requiring repentance, baptism without church discipline, Communion without confession. Cheap grace is grace without discipleship, grace without the cross, grace without Jesus Christ, living and incarnate." [Dietrich Bonhoeffer, The Cost of Discipleship (revised ed.), trans. R. H. Fuller (New York: Macmillan, 1959), p. 47]
When we evangelize the lost, are we making converts or are we making disciples? I once read on a fundamentalist Baptist Bible college's website that it was having great success making thousands of "converts" each year. (The school emphasizes "soul-winning," which prima facie does not seem to require more than a person's "accepting" Christ.) I had to wonder whether these converts truly continued in the Church or whether they slipped back into their lives immediately after their evangelists departed. Is this college making disciples? Are pastors and teachers watching over the new converts, or are the converts just being left to themselves after the evangelists get a "decision for Christ" out of them? Bonhoeffer calls us to exercise more care in evangelism and in the Christian life.
One could also pull from Bonhoeffer a much-needed warning against dead orthodoxy, the acceptance of Christian doctrine with little or no improvement in sanctification and a lack of good works. The ability to recite the creeds, confessions, and catechisms does not amount to salvation. These can certainly instruct Christians, and I value them greatly; but Christians must always remember their Shepherd, who calls them take up their crosses daily, following him (and loving him in obedience). Christians must remember what (or who) their faith is in and not take the gospel message lightly.