TAQIYYAH:
The Hadith makes it clear that Muslims are allowed to lie to kafir unbelievers in order to defeat them or protect themselves. There are several forms:
Taqiyya - Saying something that isn't true as it relates to Muslim identity (i.e whether one is a Muslim or what that means). Taqiyya is a Shiite term: the Sunni counterpart is Muda'rat.
Kitman - Lying by omission. An example would be when Muslim apologists quote only a fragment of verse 5:32 (that if anyone kills, "it shall be as if he had killed all mankind") while neglecting to mention that the rest of the verse (and the next) mandate murder in undefined cases of "corruption" and "mischief."
Tawriya - Intentionally creating a false impression by saying something that is technically true, when knowing that the listener will interpret it in a different way. This practice has a broader application than taqiyya.
Muruna - 'Blending in' by setting aside some practices of Islam or Sharia in order to advance others. Example: Sufi movement. Kuffars start practicing half of the practices of Islam, start going to dargahs and mazaars, and advance themselves half-way towards the Islamic "faith".
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