Matthew 5:14-16

Light is a common symbol in the Bible. It represents purity, truth, knowledge, divine revelation, and God’s presence all in contrast to their opposites. The Israelites thought of themselves as lights in a dark world (Isaiah 42:6; Romans 2:19). However the Old Testament spoke of Messiah as the true light of the world (Isaiah 42:6; Isaiah 49:6; cf. Matthew 4:16; John 8:12; John 9:5; John 12:35; 1 John 1:7). Jesus’ disciples are lights in the derived sense, as the moon is a light but only because it reflects the light of the sun (cf. Ephesians 5:8-9; Philippians 2:15).

The city set on a hill (Matthew 5:14) may refer to messianic prophecy concerning God lifting up Zion and causing the nations to stream to it (Isaiah 2:2-5; et al.). Since God will make the capital of the messianic kingdom prominent, it is inappropriate for the citizens of that city to assume a low profile in the world before its inauguration (cf. Luke 11:33).

The disciples must therefore manifest good works, the outward demonstration or testimony to the righteousness that is within them (Matthew 5:16). Even though the light may provoke persecution (Matthew 5:10-12), they must reflect the light of God. For the first time in Matthew, Jesus referred to God as the Father of His disciples (cf. Matthew 5:45; Matthew 5:48; Matthew 6:1; Matthew 6:4; Matthew 6:6; Matthew 6:8-9; Matthew 6:14-15; Matthew 6:18; Matthew 6:26; Matthew 6:32; Matthew 7:11; Matthew 7:21).

"If salt (Matthew 5:13) exercises the negative function of delaying decay and warns disciples of the danger of compromise and conformity to the world, then light (Matthew 5:14-16) speaks positively of illuminating a sin-darkened world and warns against a withdrawal from the world that does not lead others to glorify the Father in heaven." [Note: Carson, "Matthew," p. 140.]

"Flight into the invisible is a denial of the call. A community of Jesus which seeks to hide itself has ceased to follow him." [Note: Dietrich Bonhoeffer, The Cost of Discipleship, p. 106.]

The introduction of "good works" (Matthew 5:16) leads on to further exposition of that theme in Matthew 5:17 to Matthew 7:12.