Answer
Psalm 27, a psalm written by David, is an example of Hebrew poetry. One element of Hebrew poetry prominent in this psalm is a grammatical structure known as synonymous parallelism. For example, in the first verse of Psalm 27, the main idea and structure of the first line are synonymous with the idea and structure of the second, as shown below:
Line 1: The LORD is my light and my salvation—whom shall I fear?
Line 2: The LORD is the stronghold of my life—of whom shall I be afraid?
Both the first and second lines focus on the Lord. In the first line, David describes the Lord as his light and salvation. In the second line, David describes the Lord as his stronghold or refuge. Both lines end with the same question phrased in a slightly different manner. This parallelism allows for a fuller understanding of the first line by looking at the immediate context of the second, and vice versa.
A stronghold or refuge was a place of protection during a time of siege. The farmers and workers outside of the city would be particularly susceptible to attack as they would have been outside the city walls’ protection (Nehemiah 2:17; cf. Joshua 6:1–21). So, those farmers and workers would run to the city for refuge and protection whenever battle came. Many cities also had a strong tower, which would have been an extra layer of defense. The strong tower would give protection to those within and allow those outside to identify the city’s location whenever a battle was imminent (see Proverbs 18:10). This protection in the stronghold is why David can ask the question in Psalm 27:1, “Of whom shall I be afraid?”
Much like God is a stronghold for David, He is also David’s light and salvation. Light is utilized to see and be aware of one’s surroundings amid the darkness. The idea of “light” is often used in Scripture as a metaphor for one’s deliverance, such as in Psalm 27:1. Whenever Jesus makes the claim, “I am the light of the world” (John 8:12), He is claiming that deliverance from darkness comes through Him. Salvation, as seen in Psalm 27:1, can also be thought of as deliverance. David utilizes three terms to describe God as the Deliverer: light, salvation, and stronghold. If God is David’s Deliverer, whom should he fear?
According to the context of Psalm 27:1, David seems to be describing God as the Deliverer from physical enemies (verses 2–3). However, the Christian has also received salvation and deliverance from his or her enemies. If you have faith in the person and work of Jesus Christ (1 Corinthians 15:3–5), then God has bought you back or redeemed you. He has transferred you from the domain or authority of darkness to the kingdom of Jesus (Colossians 1:13–14). Through Christ’s provision, the Christian has been equipped for protection through the “full armor of God” (Ephesians 6:10–17).
Much as David can proclaim God is his light and salvation from the enemies surrounding him, the Christian can claim God is his light and salvation from the domain of darkness and eternal judgment (Ephesians 2:1–10). “For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord” (Romans 6:23).