It is mandatory to know who God's masters over creation are. Grand Ayat. Sheikh Jawādi Āmoli says in the first volume of his Adab Fanā' al-Muqarrabeen: "The entire realm of [dependent] existence is of the making of the pure Imams (a) and people have been made for them.." 
This is because we believe that Ahl al-Bayt (a) represent the medium between God and His creation, as well as the medium between creation and God. "Nothing rises from creation to God and nothing falls from God to creation except through them", as our jurists have often expressed.
We believe that Ahl al-Bayt (a) are the reflection of God's attributes, and thus the locus through which His legislative and ontological guardianship flow (by succession). They represent the maximum level of divine perfection that can be fathomed by the world of limitation.
We believe they represent the archetype of complete humanity that the rest of the humankind has been created only in order to follow the example of. They represent the ultimate value of submission to God, and so, following them is the avenue to fulfilling existential potential.
This is proven by a postulate in philosophy called "qā'idat al-ashraf", which states by pure logic that what is most noble (ashraf) does not emit what is ignoble (wadhee'). Rather, it only emits what is noble (shareef), from which what is ignoble then may and may not emanate.
The finest descriptions of the status of Ahl al-Bayt (a) can be found in Ziyārat al-Jāmi'ah al-Kabeera, which is a text of salutation taught to us by Imam Ali al-Hādi (a). Our jurists and religious authorities urge that we read and become familiar with it, so let us do that.
