The Stronghold

Allah Almighty said: " The word of La ilaha ill-Allah (there is no God but Allah) is my stronghold (then whoever acknowledges this, will enter my stronghold) and will be saved from my punishment." and Imam Reza (AS) continued: " There are few conditions regarding this enterance and I am one of its conditions". 

To get a better understanding of this heavenly narration , see Monotheism and Leadership.