There is a good article from a godly scots preacher but I can only quote part here. Maybe we can as believers not confess sin as we ought-seems to be the major part of prayer of godly men used in evangelsim
Robert Murray M'Cheyene's Personal Confessions I find that the devil often makes use of the confession of sin to stir up again the very sin confessed into new exercise, so that I am afraid to dwell upon the confession. I must ask experienced Christians about this. For the present, I think I should strive against this awful abuse of confession, whereby the devil seeks to frighten me away from confessing. I ought to take all methods for seeing the vileness of my sins...
'As to your question "Why?" This is tricky, and I do not know the answer. Do you? Maybe this is a time when all the Gentile sheep have been brought into the fold, and there is none left to find...' John uk
Just listened to a Glasgow sermon, a free church cont. who began evangelsing a particular area of glasgow whilst praying for a church building-well God has granted the building in an amazing way. You could be right and the answer to 'why' God alone does know, yet there is something we can do as believers-the sermon just providentially heard might grant you an answer if you care to listen http://www.sermonaudio.com/sermoninfo.asp?SID=1219081511483
Also in Glasgow there is a street preaching baptist church here on sermonaudio with the actual street preaching messGES, add another 2 evangelising calvinistic churches in that city also http://www.sermonaudio.com/source_detail.asp?sourceid=stenochbaptist
The rest of the UK I know not,do you know of the Fulton St revival New York in the late 1850s. Jeremiah Lanphier began with a prayer meeting? Mentioned in free church cont mag http://www.masterstrumpet.org/issue4.pdf
Maybe Michael Hanerek can enlighten us further?
Evangelism lacking REAL PRAYER IS possibly ONE ANSWER TO the question why?