What Kind of Priest? (Hebrews 2:14-18; LD 6)

Hebrews tells us that Christ destroyed the devil and death.  If this is true then why do people still die?  How can it be that the devil still exists and tempts people? Is the book of Hebrews over stating its case about the effects of Christ’s work or are we missing something?  If we are missing something then how can we be encouraged by the work of Christ?  What is definitive about His work?