>Can 3 uh-uhs make you a Christian?

>Struck by this comment on a friend’s facebook:

“Evangelism has been reduced, in many churches, to the “abc’s” admit, believe, confess or as one preacher put it, “if you can say three uh huh’s you can be a Christian” Paul Fries
Is it not odd that the “formulas” for evangelism are not found in Scripture? 
Reading the Word can spoil you for a lot of contemporary (within, say, the last 150 years) ideas and concepts of ministry.
It appears that the Lord Jesus always made it easier to say “no” to His “invitation” than “yes.” It is hard to imagine Jesus, or any apostle, saying “Every head bowed, every eye closed.” The call was adamant, demanding, and public.
Can “invitations” be good? Yeah, as long as it is made crystal-clear that “coming forward,” “going to the prayer room,” or even raising hand for prayer has no merit in and of itself. If the purpose of the invitation is solely to get the person to a place where they can ask questions, be pointed to the gospel, etc; that is okay (IF adequate time is given to each individual respondent, rather than a rush to “pray the prayer” ((which is not found anywhere in scripture)))
It seems vital, to me, that anyone who “gives” invitations need not necessarily learn “how” to give an invitation, but should first do a study of the “invitation system.” It isn’t that old, and perhaps that, in itself, should be a warning?