Misunderstanding something leads to incorrect actions or reactions to what we hear or see. It can cause trouble, fight, losses or even death like a doctor who misunderstands a patient's sickness and prescribes the wrong medication.  To misunderstand the righteousness of God and His requirements will lead to wrong methods and content of our evangelism. It is crucial that the content, as well as the method of our evangelism, carries a correct understanding of who God is and how a sinner gets into a right relationship with Him.