Q. Why do we sometimes give a new name to a seriously-ill patient?
A. Some believe that a new name for a seriously-ill patient is intended to fool the angel of death. Is there a deeper, less folkloristic rationale? Possibly the name change expresses the deep concern of family, friends and the community for the sick person and, in that sense, it is a form of prayer.
A rabbinic idea is that changing your name can change your destiny (Rosh HaShanah 17b). Sarah is an example: as Sarai, she was barren; after she became Sarah, she bore a child (current practice is not to eradicate the original name but to add a further name such as “Raphael” [God is a Healer], “Chayyim” [Life], etc.).
This is not to advocate change for change’s sake. However, we can always benefit from a new beginning, a new challenge and a new set of circumstances.