A door leading towards a destination. Intercession can aptly be liked to a door because it is through Intercession that the intended destination is reached.
Amongst the most contested and misunderstood beliefs of the Shi’a is Intercession. Many non-Shi’as view this practice as a direct violation of the Islamic belief of pure monotheism (Tawheed) and have accused Shi’as of practicing Polytheism (Shirk).
Unfortunately such accusations and misunderstandings of the Shi’a philosophy of Intercession are based upon a lack of understanding of Shi’a beliefs as well as shallow and isolated reading of Quran verses.
Shi’a theologians have been quick to point out that constantly within the realm of creation, we as individuals use intermediaries, for example if we are hungry, we eat food to satisfy our hunger, if we are thirsty, we drink to quench our thirst. In both of these cases, we are relying upon sources which are seemingly not Allah directly, however in neither of these cases would one be accused of committing God, due to the fact that in both cases neither the drink nor the food is viewed as an independent self-sustaining source of nourishment but is viewed as a provision (Rizq) from God.
Likewise in the case of intercession, none of the Muslims who believe in the intercession of Prophets and Imams believe that these individuals possess power independent of Allah.