Imam Ghazali states:
Your belief that you are better than others is sheer ignorance. Rather you ought not to look at anyone without considering that he is better than you and superior to you.
Thus, if you see a child, you say, ‘This person has never sinned against God, but I have sinned, and so he is better than I.’
And if you see an older person, you say, ‘This man was a servant of God before me, and is certainly better than I.’
If he is a scholar, you say, ‘This man has been given what I have not been given and reached what I did not reach, and knows what I am ignorant of; then how shall I be like him?’
And if he is ignorant, you say, ‘This man has sinned against God in ignorance, and I have sinned against Him knowingly, so God’s case against me is stronger, and I do not know what end He will give to me and what end to him.’
If he is an infidel, you say, ‘I do not know; perhaps he will become a Muslim and his life will end in doing good, and because of his acceptance of Islam something of his sins will be taken away, as a hair is taken from dough; but as for me – God is our refuge (God grant it does not happen) – perhaps God will lead me astray so that I become an infidel and my life ends in doing evil, and then tomorrow he will be among those brought near to God and I shall be among the punished.’
Arrogance will not leave your heart except when you know that the great man is he who is great in the sight of God Most High. That is something which cannot be known until the end of life, and there is doubt about that (the end and whether it will be good or bad).
So let fear of the end occupy you and keep you from making yourself out, despite the doubt about your end, to be above the servants of God Most High. Your certitude and faith at present do not exclude the possibility of your changing in the future; for God is the Disposer of hearts; He guides whom He will and leads astray whom He will.
Extract from Imam Ghazali’s Bidayat al-Hidaya or ‘The Beginning of Guidance’