Not a hair lost vs Persecution

The phrase “not a hair of your head will be lost” can be found in Luke 21:18. It’s important to interpret it in the context of the surrounding verses. In Luke 21:16-17, Jesus speaks about the persecution that His followers will face: “You will be betrayed even by parents, brothers and sisters, relatives and friends, and they will put some of you to death. Everyone will hate you because of me.” Then in verse 18, He says, “But not a hair of your head will perish.“

The phrase “not a hair of your head” is idiomatic to Greek and is not intended to be taken literally as though there were a threat to one’s personal mane. Here is one of several other examples in Scripture: Acts 27:34: “Now I urge you to take some food. You need it to survive. Not one of you will lose a single hair from his head.” No immediate impending threat to any of their heads existed (e.g. no one was being threatened with beheadment). In all likelihood many of the prisoners who swam ashore after the ship wreck actually did lose a few hairs in the water, but the meaning is clear, that they would all survive perfectly well.

Now, Scripture does indeed make many promises of personal protection, by choosing the narrow path that leads to life. Certainly we want to make every effort to follow that narrow path and to enter into the faith for God’s protection. It is however a bit dangerous to take metaphorical idioms and try to press them into a literal meaning, because if the barber goofs and you do lose some hair, it might make you doubt the Lord’s promises.

Romans 8:38-39 underscores the unbreakable bond between Believers and God’s love, assuring them that nothing in all creation can separate them from the love of God in Christ Jesus.

Psalm 91 https://biblehub.com/psalms/91.htm is a popular Psalm of promise for protection.

He that dwelleth in the secret place of the most High shall abide under the shadow of the Almighty. I will say of the LORD, [He is] my refuge and my fortress: my God; in him will I trust. Surely he shall deliver thee from the snare of the fowler, [and] from the noisome pestilence. He shall cover thee with his feathers, and under his wings shalt thou trust: his truth [shall be thy] shield and buckler. Thou shalt not be afraid for the terror by night; [nor] for the arrow [that] flieth by day; [Nor] for the pestilence [that] walketh in darkness; [nor] for the destruction [that] wasteth at noonday. A thousand shall fall at thy side, and ten thousand at thy right hand; [but] it shall not come nigh thee. Only with thine eyes shalt thou behold and see the reward of the wicked. Because thou hast made the LORD, [which is] my refuge, [even] the most High, thy habitation; There shall no evil befall thee, neither shall any plague come nigh thy dwelling. For he shall give his angels charge over thee, to keep thee in all thy ways. They shall bear thee up in [their] hands, lest thou dash thy foot against a stone. Thou shalt tread upon the lion and adder: the young lion and the dragon shalt thou trample under feet. Because he hath set his love upon me, therefore will I deliver him: I will set him on high, because he hath known my name. He shall call upon me, and I will answer him: I [will be] with him in trouble; I will deliver him, and honour him. With long life will I satisfy him, and shew him my salvation. [Psa 91:1-16 KJV]

Footnotes:

1. Psalm 91:3 One who catches birds in a trap or snare
2. Psalm 91:4 A small shield
3. Psalm 91:12 lift
4. Psalm 91:12 strike
5. Psalm 91:14 exalt him
6. Psalm 91:16 Lit. length of days