Hadhrat Maseehul Ummat Maulana Mohammed Maseehullah Khan
Consider yourself to be the most inferior, so much so, that if you observe with your own eyes another indulging in the worst of vices then too you shall not despise him/her, nor shall you consider yourself nobler than him/her. On the contrary one should fear and bear in mind that it is very possible that the perpetrator of the vice may resort to sincere taubah and become a person of high piety while the one who had despised the sinner become ensnared (Allah forbid !) in the meshes of the nafs and shaitaan and be diverted from Ibaadat and obedience. One has no certainty regarding one's end. One, therefore, has no basis for regarding another with contempt.
We were told this by our Shaikh. It is the first lesson we learn when taking the path of Tasawwuf otherwise the path to purification remains closed. May Allah give us the Tawfiq to strive in this Dunya for His cause.
Peace and Blessings on the Prophet and His family and his Sahaba.