In chapter 6 the structure of the Sermon on the Mount becomes elusive. Matthew is drawing sayings from Q which are only loosely linked together. Nevertheless, there is a theme which connects most of them: trust in God above all else.
Matthew recognizes the strain that disciples will feel in making the right choices in life. He insists that there must be a priority and that God must be first. He asserts that heavenly treasure is superior to earthly treasure (verses 19-21). He warns that a person can only serve one master (verse 24). He advises that those who would be free from worry must put the kingdom of God first (verse 33).
The tone in these verses is not harsh but encouraging. Examples are used to lead the reader to recognize the wisdom of trusting in God. Matthew argues from the lesser to the greater: if God cares for the birds of the air and the lilies of the field, how much more will God care for you (verse 30)? Here Matthew uses one of his favorite phrases, “you of little faith.” Occurring five times in the gospel, this gentle rebuke is directed to disciples whose faith is real but faltering. It is Matthew’s way of saying, “Don’t be afraid. Don’t pull back. Don’t believe less—believe more! Doing so will provide you with a richer life.”
Matthew frequently describes Jesus’ disciples as those of “little faith.” Their faith is little when Jesus teaches them about the lilies of the field (6:30) and the mustard seed (17:20), when they cannot understand the miracle of the loaves and fishes (16:8), and when Jesus calms the sea (8:26). The gospel does not suggests that this incomplete faith will be overcome. In Matthew disciples never arrive at “great faith” or “perfect faith.” Doubts and imperfections continue to characterize the life of every believer.
Peter displays little faith dramatically. In Matthew 16:13-20 Jesus will describe Peter’s faith as a solid rock foundation which will serve the community. In Greek, Peter’s name is the same word as “rock.” Matthew’s readers would hear the connection: “You are Peter [Petros], and on this rock [petra] I will build my church” (16:18). But such solid faith does not fully describe Peter. In 16:21-27 Jesus will rebuke Peter for not accepting the message of the cross saying, “you are a stumbling block to me” (16:23). This image reflects a passage of Isaiah which describes a rock or stone over which the inhabitants of Jerusalem will stumble and fall (Isa 8:14-15). The “rock” Peter is both a firm foundation and a stumbling stone. in 14:22-33 when Peter tries to walk on the water, doubts, and then begins to sink. As Jesus pulls him up out of the waves, he says, “You of little faith, why did you doubt?” (14:31). Describing Peter’s situation as one of “little faith” is certainly a rebuke, but it is a gentle one. It describes a situation in which real faith is present, but doubt is as well—a mixed condition in which belief and weakness coincide. Like the rest of the disciples who are “of little faith,” Peter is both a real believer and also one prone to weakness and doubt.
Matthew is suggesting that our faith is much like Peter’s. We really believe, but we never believe completely. Although our flaws like Peter’s can cause others to stumble and fall, our faith, if it is real, can provide a foundation upon which the belief of others can stand. Our faith is seldom great and never perfect, but God still calls us to change the world. In that mission, our little faith will have to do.
Faith, for Matthew, is very practical. In these verses he argues that trusting in God is both wise and productive. It will provide a life free from worry and fear. Trusting in God does not simply lead us to the kingdom. It increases our joy and confidence as we proceed towards it.