Any discussion with the Shia'a revolves around the doctrine of Imaamat, since this is their belief that seperates them from mainstream Muslims. Yes this doctrine has no support
in the Qur'an, the word of Allah. (see also this
As for your questions, Br. Khaldun has pointed out that the Prophet saws did promise other companions paradsie, like the ten he listed. Even in the Qur'an, in verse 48:10 Allah swt tells us He is pleased with all
the companions who gave allegiance to the Prophet saws at ther treaty of hudaybiyah. Who are we to be displeased with those whom Allah swt is pleased with? And in verse 48:29 Allah swt promises these same believers paradise. That is the promise of Allah that no one can change.
As for muta'ah, this was a practice that was temporarily allowed in the early stages of Islam, just as alcohol was temporarily allowed. The reason being that the Islamic laws were implemented gradually to allow people the opportunity to develop and adjust - if they were imposed immediately the religion would be too difficult for the Makkans for whom Muta'ah and alcohol were part of daily life. Nevertheless, later, both Mutaa'a and alcohol were forbidden in Islam.
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