The heart is like a bright mirror; repugnant traits are like smoke and darkness which, when they touch it, darken it so that tomorrow one will not see the Divine Presence and it will become veiled (to one’s view). Good traits are the light which reaches the heart and wipes away the darkness of sin. It is for this that the Prophet (peace and blessings be upon him) said: “Follow a bad deed with a good (deed) so that (the bad) may be erased.” At the resurrection, it will be the heart which comes into a desert, either bright or dark. None will be saved except him who comes to God with a sound heart. (Qur’an 26:89)
A person’s heart, at the beginning of creation, is like (raw) iron from which –if a person keeps it as he should—is made a shining mirror that displays the entire universe. If not, it will all rust and become so that nothing will be reflected in it. As God Most High said: Nay, but that which they have earned is rust upon their souls. (Qur’an 83:14) [Al-Ghazali On Knowing Yourself and God, tr. Muhammad Nur Abdus Salam, pp. 18-19]
This world was God’s storeroom. Lined up on the shelves were billions of clay vessels of all sizes and shapes, each one unique. When God needed a particular vessel, God would reach directly for it. Only if the vessel was completely empty could it be used. If it was not completely empty, it remained on the shelf, for it could not contain what God needed it to contain; it could not be used.