To him who overcomes I will give him a white stone, and on the stone a new name written which no one knows except him who receives it. (Revelation 2:17)
From a chapter on heaven, C.S. Lewis in The Problem of Pain comments:
I am considering not how, but why, [God] makes each soul unique. If He had no use for all these differences, I do not see why He should have created more souls than one. Be sure that the ins and outs of your individuality are no mystery to Him; and one day they will no longer be a mystery to you. The mould in which a key is made would be a strange thing, if you had never seen a key: and the key itself a strange thing if you had never seen a lock. Your soul has curious shape because it is a hollow made to fit a particular swelling in the infinite contours of the Divine substance, or a key to unlock one of the doors in the house with many mansions. For it is not humanity in the abstract that is saved, but you—you the individual reader… Blessed and fortunate creature, your eyes should behold Him and not another’s. All that you are, sins apart, is destined, if you will let God have His good way, to utter satisfaction. …God will look to every soul like its first love because He is its first love. Your place in heaven will seem to be made for you and you alone, because you were made for it—made for it stitch be stitch as a glove is made for a hand.