Note 2 at Lk. 21:18: Jesus speaks of the disciples as being betrayed by parents, brothers, relatives, friends, and some shall even be put to death (Lk. 21:16). Yet, the amazing statement of Christ is that not a hair of their head would perish (Lk. 21:18). The very context of this statement speaks of some of the disciples dying, so this is not a promise that no physical harm would ever come. This could only refer to the resurrection.

The Lord views everything in the light of eternity. Man tends to view things in the context of our brief life here on earth. From man's perspective, a person who dies for his faith in Jesus has lost a great deal. But from Jesus' viewpoint, a martyr hasn't lost a thing. Even the very hairs of our head are numbered (Mt. 10:30; Lk. 12:7) and will be resurrected, plus, we will receive a better resurrection (Heb. 11:35).