The "*" is to prevent writing out in full the name of a false "gxd." This is different from avoiding spelling out, because of reverence, a reference to the True G-d. Most Jews/Noachides use the "X" (X, Xian, Xmas, etc.), but I long ago decided to let the chr*stians keep the "X" and use it for themselves without feeling like they were denying their faith by doing so.
This answer is not intended to be antagonistic either.
The "*" is to prevent writing out in full the name of a false "gxd." It has the opposite effect. * is a wildcard operator, so it picks up any letter and could inadvertently include other gods or places, such as Gilead.