A Blanc Book

It's as old as a hundred years old tree in the middle of rain forest. Unexplored and protected. No one known of what could it be used for as it's just too old but those who appreciate it will get to know the secret. It's been passed down from generation to another generations and only the one who's worthy would open it. Many were curious but they do not dare to open it as it's said to have curse upon those who's not worthy opened it. Calamity will befall upon them and their children. This believe too had been passed down from the older generations. However, none of them do not know how to judge whether they are worthy.
"This is the book that had been passed down from your great grandfather before your grandfather passes it to me." Said the old man who's bedridden and were about to take his last breathe.
"Only open it when you deem you're worthy and when it's necessary as it contains the secrets of our family."
"But father, it's just an old myth. It's like a folktale." His son took the book and placed it on his palm very carefully.
"It's more than just a myth, my son."
"Okay father, I will hold on to this. Please rest well." As the son finishes his words, the old man took his last breathe.
The only thing left was an old book which means almost nothing but being awfully blanc. It's just a book that's blanc.