Melinda Penner notes how misusing the "sinner's prayer" can undermine the point of salvation - discipleship:
Sadly, sometimes the "sinner's prayer" is treated as almost a magical formula. Some evangelism encounters end with the prayer and that sums up the fulfillment of duty for the evangelist. The point of salvation is discipleship, not just a prayer. Many times I've heard the answer to the query whether that wayward friend or family member is a Christian that they "prayed the prayer." The book of James should cause grave caution about drawing much comfort from merely praying a prayer. Consequences will follow from the indwelling of the Holy Spirit.In "A More Spontaneous and Genuine Evangelism," Jim Elliff identifies factors that diminish our boldness in telling others about Christ. Among them:
....we have the mistaken notion that evangelism is a choreographed set of ideas well laid out, perfectly transitioned and flawlessly presented. Forget it. It's not this way. Many of us have tried this with frustration. It is much better to think of evangelism the way the Bible does—"sowing the seed" in any way you can. Any of us can do that. Ever seen a weed grow in an otherwise barren parking lot? Somehow the seed got there and flourished. The simple word in the right place, or the tract well-placed might be the means God uses. Well-oiled presentations frustrate because there is no room for serious questions and discussion on the one hand, and it rules out the less verbal among us, on the other. Rejoice over even the smallest of advances! You are sowing the seed.
I don't wish to say that there is no value at all in memorizing a set plan. But there are many limitations to such methods. The proof is that the enthusiasm for such plans often dies away after the weeks of concentrated effort are finished. Also, among the least desirable aspects of most of these plans is the fact that they may not encourage listening to the person you are addressing. It's primarily about getting a set of concepts across, rather than finding out the real questions people have and the dilemmas they face.