Read Joel 2:12-17. 
So much of religion can be accomplished by the head and the hands. Religion is a matter of do’s and don’ts; we learn to follow these simply by mental and physical focus. However, while religion may be achievable through the will power and of man, will power does very little to further the kingdom of God. In order to receive the blessings and promises of spiritual renewal and transformation found in Scripture, the heart must supersede our mind or our strength. When we operate out of our own will, we realize not only our strengths but also our limits. The strength of God,on the other hand, becomes unavoidably apparent when our hearts are opened, and we are willing to follow and not lead. We are hesitant to share our hearts, and this is no different with God. We view our hearts as our own private space where only we are allowed entry. But the only way to truly know God is to be one with him, and the only way to be one with him is to give him access to that which is most dear to us: the heart. By allowing him to restructure and reveal our heart to us, God not only shows us the dangers of our darkest desires but the beauty of his unlimited love. Once this bond has been shared, the obstacles that once existed in our lives are taken down, and we are free to run with a God that intends to take us places where only he exists and only love of a renewed heart reigns.