Invitation

[Mr M.Saber]

-- The end result is the same. "Make sure" implies the person should take some definite action in order to be certain that something is ok, and "be sure" just says to be certain it is so.
- Make sure the door is locked. = Go over there and check it.
- Be sure the door is locked. = You don't have to check it again if you are really certain it is locked.