This is Christ’s first recorded sermon. Matthew has just introduced us to the Lord’s ministry by telling us that vast crowds responded to his teaching, preaching, healing, and casting out of demons, and now he brings us examples of each of these.
Those who treat this sermon as moral instruction for the whole human race have never understood its real challenge. It is not possible for those outside the kingdom of heaven to live by these standards. True obedience must come from the heart, and therefore the heart must first be changed in conversion, otherwise it cannot produce fruit acceptable to God. ‘A corrupt tree can only bring forth evil fruit.’ The sermon assumes what the Bible assumes throughout: that a person can only be justified by faith.