Judaism recognizes the positive value of "Emunah" (generally translated as faith, trust in God) and the negative status of the "Apikorus" (heretic), but faith is not as stressed or as central as it is in other religions, especially compared with Christianity and Islam. It could be a necessary means for being a practicing religious Jew, but the emphasis is placed on true knowledge, true prophecy and practice rather than on faith itself. Very rarely does it relate to any teaching that must be believed. Judaism does not require one to explicitly identify God (a key tenet of Christian faith, which is called Avodah Zarah in Judaism, a minor form of idol worship, a big sin and strictly forbidden to Jews). Rather, in Judaism, one is to honour a (personal) idea of God, supported by the many principles quoted in the Talmud to define Judaism, mostly by what it is not. Thus there is no established formulation of Jewish principles of faith which are mandatory for all (observant) Jews.