Sometimes knowledge is a condition for the validity of faith and an obligatory condition for it, and sometimes faith is a condition for the validity of the knowledge of revelation and an obligatory condition for it, except that faith contains a purification of the heart from the veil, and knowledge is a purification of the heart from ignorance, doubt, and hypocrisy, so purify your heart with the two purifications. You will excel in this in the worlds and attain the knowledge of the two fists with it. For God has made it obligatory for us to believe in Himself, and from Himself His names, His angels, His books, and His messengers. We do not differentiate between any of His messengers, despite our knowledge that God preferred some of them over others as messengers and prophets, then He forbade us from giving preference among the prophets by analogy or consideration, for the servant does not judge God in anything.