How do you open the safe?

If you are talking about the safe at the monestry, you must read the letter on the desk, and the letter sould have a date that shows up in green letters.

I think the date is 12-10 or something like that, then on the second page of the letter it says right, left, right, left this tells you to start off going left until you get to the number 1.

Press X, then go left until the number 2 then press X, and then go right again until 1, press X, go left to 0 then press X, use left trigger button to go left and right trigger to go right.

This should open the box. you will receive a book, then place the book at the alter on the bottom level.

However you will go back into that same room, and read the letter again and a new letter with new date and new directions will show up, and follow the same way as above, it will give you a life of the gods orb.

The combination to the safe on the second try is right to 1 left to 4 right to 1 and left to 0. The rest is self explanitory as the combination and the directions are listed in the monks journal.

The combination to the safe isn't what the last person wrote .
The combination is left all the way to 2 hit x then turn right to 7 hit x then turn right to 1 hit x then turn left to 2 hit x and that will give you the book that you need to open the tomb below that floor. Later you will have to open the safe two more times. The second combo is 1,4,1,0. And the third one is left to 1 left to 2 right to 2 and left to 3 hope this helps.
Good luck.