"Minimizing the importance of transformed feelings makes Christian conversion less supernatural and less radical. It is humanly manageable to make decisions for the will of Christ. No supernatural power is required to pray prayers, sign cards, walk aisles, or even stop sleeping around. Those are good. They just don't prove that anything spiritual has happened. Christian conversion, on the other hand, is a supernatural, radical thing. The heart is changed. And the evidence of it is not just new decisions, but new affections, new feelings."
(Desiring God, p. 89, John Piper)