The problem is that many people cling to the symbol but never understand the reality it is intended to represent. Most likely, tens of thousands of people have 'invited Christ into [their] hearts,' thinking that a mystical experience is what saves them. Then, they go on their merry way, living their lives as they did before. If you were to ask them, 'How do you know that you are going to heaven?' they would respond, 'Because I invited Christ into my heart.' But if you probe, there is nothing beneath the shallowness of that reply. They did what someone told them to do, but never really embraced the Savior.