Question
What does Psalm 91 say about God's protection? (and does God promise to keep us safe?)
Analysis
What the psalm promises
Psalm 91 piles up images of security: a shelter, a shadow, a fortress, a shield, wings to hide under (Psalms 91:1–Psalms 91:4). The one who trusts God need not fear the terror of night or the arrow by day (Psalms 91:5; Psalms 91:6), and God's angels are appointed to guard them (Psalms 91:11). The psalm's climax is God's own promise: 'Because he holds fast to me in love, I will deliver him… I will be with him in trouble' (Psalms 91:14; Psalms 91:15). Note that last line: not 'no trouble,' but 'with him in trouble', God's presence and rescue, not the absence of all hardship.
How to read it honestly
The Bible does not promise believers a pain-free life, and it would be a misuse of Psalm 91 to claim it does, the very passage was Satan's tool to tempt Jesus into presumption (Matthew 4:6; Matthew 4:7). Jesus was clear: 'in the world you will have tribulation', followed by real comfort, 'But take courage; I have overcome the world' (BSB, John 16:33). The deepest security the Bible offers is not that nothing bad will happen, but that nothing can separate God's people from His love, not trouble, danger, or death (Romans 8:35; Romans 8:38; Romans 8:39). Read that way, Psalm 91's comfort is real and unshakable, without becoming a magic charm.
Other protection passages
The theme runs throughout Scripture: 'The LORD will guard you from all evil; He will preserve your soul' (BSB, Psalms 121:7; Psalms 121:8); the valley of the shadow, yet 'I will fear no evil, for you are with me' (Psalms 23:4); 'the name of the Lord is a strong tower' (Proverbs 18:10); and 'Do not fear, for I am with you' (BSB, Isaiah 41:10).