There is three possibilities:

You may have problem with Resource Bundle in general,
be sure that this file is placed in WEB-INF/classes.

But if you have problem with the farsi  characters, you
can save the Resource Bundle file as Unicode and use
native to ascii command to generate the equivalent
ascii code.

Yet another problem may be bad fonts  of html.
If you let me know exactly what the output is, I can
tell you what the problem, exactly is!