What does it mean to believe in the gospel with your heart rather than just your head?
Believing the gospel with the heart means trusting it from the inner person, not merely giving mental assent to historical facts. Head knowledge agrees Jesus lived, died, and rose; heart belief is that central part of us relating to the spirit world, where God begins and finishes His work, and on which eternal destiny rests.
Les teaches that many people assume that if they simply believe, they are all right, but most people in our nation only believe the historical fact that Christ lived and died, and maybe give a head-knowledge assent that He rose from the dead. That is not believing, because believing does not come from the head but from the heart. The heart here is not the pumping organ that moves blood through veins and arteries; it is the very central part of us that has a relationship with the spirit world, and it is there that God must begin and finish His work. So when Les speaks of believing, trusting, and having faith in the gospel, he means a true heart belief, not just head knowledge. He cites the expression that many will miss heaven by twelve inches because they had it in the head but never got it in the heart. A person must be sure that they are believing not merely by mental assent, but because God has opened their ability to believe and they have trusted their whole eternal destiny on it. Those without that kind of heart faith face eternal doom.