The worst thing to happen to evangelism
I think the number 1 thing that affected evangelism for the worse and created all this drama that now happens when people think they are sharing the Gospel is that the church has taken a term from the bible and given it a new meaning. That word is repentance. The twisting and redefining of that word has changed the gospel from a "come as you are" to a "clean yourself up first". It took a comment from Jesus of hope and guidance and twisted it into an order or demand. Your definition of this word completely changes scripture, thoughts, words, and interpretation.