Is It Illegal To Discriminate in Public Notices and Advertisements?

I responded to an advertisement inviting only Jewish teachers to apply for an open teaching position at a Synagogue. I am Chrisitan and applied anyway because I believe this practice of restricting who can apply to be discriminatory. Are discriminatory practices in advertising illegal?

By Deskin Law Firm
It is unlawful for any employer to print or publish any notice or advertisment stating a preference, limitation, specification or discrimination based on a protected classification EXCEPT where that advertisment involves a qualification that is an objective and absolute qualification for the job for purposes of religion, sex and national origin only.

I Noticed an Advertisement that States a Discriminatory Preference, What Can I do About it?