Mattityahu 10:32-33

Therefore, everyone who shall declare publicly the Ani Maamin hoda'ah of me, before Bnei HaAdam, I will make hoda'ah (acknowledgment) of him before Avi sh'ba'Shomayim. But everyone who makes hakhchashah (denial) of me, I also will make hakhchashah (denial) of him before Avi sh'ba'Shomayim.