Is a person that hears God insane or really hearing it?

[bore]

Delusional is a better descriptor than insane. Insane is probably to found a cult or to deny that the square root of four is two because God told you something different, so to speak.

2 is a square root of 4 but the square root of 4 is not 2

[bore]

Delusional is a better descriptor than insane. Insane is probably to found a cult or to deny that the square root of four is two because God told you something different, so to speak.

2 is a square root of 4 but the square root of 4 is not 2

You must be either an idiot or a mathematician (Is there really a difference?) to be that pedantic about someone referring to the principal square root as "the square root" instead of "a square root".

If you want to sacrifice rigour for something ghastly like usefulness then by all means do, but I have no desire to become an engineer.