The argument for that takes the form ranging from, if they were right, then everyone else has lived their only lives on an empty lie, to asking what if Buddhists were right, what if Muslims were right, what if Jews were right, etc.
All this affirms one thing- faith is what is the key.
Requiring incredible evidence, is a sign of wavering faith.
Requiring incredible evidence is a sign of wavering faith, but Biblical faith is not one that has no evidence, but like getting marriage, salvific faith is a step based upon evidence sufficient to warrant it. Abraham did not become a convert thru Baker’s Encyclopedia of Christian Apologetics, useful as that can be, and the miraculous changes which result when a soul becomes born again and continues in the faith testify to a cause which upon close examination overall can defy known natural explanations. Rational souls do not write thousands of hymns about Jesus because they are imagining things, and radical changes in heart that where sought in vain, but resulted when a soul simply prayed a contrite prayer to Jesus, ought to make an unbeliever at least be open to the possibility of God.
As for NDE’s, there is much research by secularists that make it very hard to deny life after death, at the least. I think these links still work.
http://video.google.com/videosearch?q=near+death+experiences+habermas&sitesearch=video.google.com (Research NDE)
http://www.youtube.com/watch?v=_I9-XxBAEsQ (BBC - The day I died)
http://video.google.com/videoplay?docid=6547221602055506348&q=mickey+robinson&total=57&start=0&num=50&so=0&type=search&plindex=1 ( mickey robinson — air crash to Christ)