Today, most Christians who attend a church regularly are older.  In past generations, it was left up to younger people to pass the word on to the next generation.  Now, older believers are desperately needed: we must make sure that the faith remains alive.  As we are told in Psalm 92, the aged "still bear fruit" and "they are ever full of sap and green".  Indeed, we must be tall, strong, and with deep roots, "like a cedar in Lebanon".