For this reason Christ is the mediator of a new covenant, that those who are called may receive the promised eternal inheritance—now that He has died as a ransom to set them free from the sins committed under the first covenant.  

In the case of a will, it is necessary to prove the death of the one who made it, because a will is in force only when somebody has died; it never takes effect while the one who made it is living.  Hebrews 9:15-17 NIV