Leslie Keeney wrote this insightful piece about why sharing our personal testimonies is no longer the best way to share the gospel:
The problem with this method is that it doesn’t work anymore. It might have worked 20 or 30 years ago, but in 2013 any post-modern worth his salt will respond “that may be true for you, but it’s not true for me.” And well he should. If the person sharing his faith is saying that you should try this because it worked for him—if he is basing his argument for following Christ on his own experience—then it’s only fair that the person responding should be able to say that his experience is just as valid.
In a way, the Christian who uses only his own experience to tell non-Christians about Jesus is giving the post-modern the home-field advantage. He is implicitly agreeing that what matters most is personal experience, not truth.
You can read the whole thing here.