The Christian’s Commission
Matthew 5:14 (ESV) … “You are the light of the world. A city set on a hill cannot be hidden.”
Jesus again used the emphatic “you,” and again clearly stated that this is already what a believer is, not something he might become. It is the nature of a kingdom servant to be light in the world. Any believer who fails to function as light is going against his nature as God’s new creation. The believer has no light inherent in himself. The believer’s light is a reflected light. Believers are to make certain that nothing comes between them and their source of light (2 Cor. 3:18; Phil. 2:13–16).
Both a city on a hill (5:14) and the lamp … on its stand (5:15) fulfill their function by being elevated, so their light can be seen by many people over a broad area. Jesus himself explained the application of this principle in 5:16. The light represents our good works, which must be done with such integrity that all who see have no choice but to credit our Father in heaven. The Christian’s life and influence is to be visible and obvious, not secret or hidden. We must not camouflage our devotion to Christ, but humbly do all we can to allow its truest colors to be seen where we live.
The term translated praise means “to make manifest or visible.” When we shine our light before others by living righteously, we are making visible the character of the Father. Some people might claim a contradiction between the instruction here to Let your light shine before men, and in 6:1–6, Be careful not to do your acts of righteousness before men, to be seen by them. However, there is a great difference between the two passages, and it has to do with who is glorified by the good works. In one case attention is drawn to God; in the other, it is drawn to self. It is the Christian’s commission to live in such a way as to make God visible in a world that is blind to him.
This is the first time Matthew calls God Father. It is a wonderful, new emphasis on personal intimacy for the believer. Matthew used this word forty-five times. And while the fatherhood of God was not unknown in the Old Testament, here it is endowed with a very personal sense (Mark 14:36; Rom. 8:15; Gal. 4:6). The king wants his people to know that his kingdom involves a deeply personal relationship with God. It is so much more than a religious or organizational connection.
 Weber, S. K. (2000). Matthew (Vol. 1, pp. 62–63). Nashville, TN: Broadman & Holman Publishers.