Assalamu 'Alaykum wa Rahmatullahi wa BarakatuhuBROTHERS AND SISTERS
Allah Subhanahu wa Ta'ala the Most High says in the glorious Quran:
Whoever is blind in this world, he will be blind in the hereafter. (Sura Bani Isra'il, 72)
It is not the blindness of the eye's of one's head but the blindness of the eye's of one's heart that will prevent one from seeing the light of the hereafter.
As Allah Subhanahu wa Ta'ala Most High says:
For surely it is not their eyes that are blind, but their hearts which are in their breasts. (Sura Hajj, 46)
The only cause of the heart becoming blind is heedlessness, which makes one forget Allah Subhanahu wa Ta'ala and one's function, one's purpose, one's promise to Him, while one is in this world. The principle cause of heedlessness is ignorance of the reality of the divine laws and orders. What keeps one in this of ignorance is a darkness that completely covers one from the outside and fully invades one's being. Some of the properties of this darkness are arrogance, pride, envy, miserliness, vengance, lying, gossiping, backbiting and so many other hateful traits. It is these traits that reduce the best creation of Allah Subhanahu wa Ta'ala to the lowest of the low.
To rid oneself of these evils one has to cleanse and shine the mirror of the heart. This cleansing is done by acquiring knowledge, by acting upon this knowledge, by effort and valour, fighting against one's ego (nafs) within and without oneself, by ridding oneself of one's multiplicity of being, by achieving unity. This stuggle will continue until the heart becomes alive with the light of unity - and with the light if unity, the eye of the clean heart will see the reality of Allah Subhanahu wa Ta'ala's attributes around and in it.
Extract from the Secret of Secrets - Hadrat Abd al-Qadir al-Jilani Rahmatullahi 'alayh(May Allah Subhanahu wa Ta'ala continuously perfume his resting place)