"If you knew what I know, you would go out to the jungle, weeping and crying and leave your property unguarded. But your hearts are heedless of the requirements of the Hereafter and you have, before you, worldly hopes and aspirations. That is why the world has become your master and all your activities are directed towards it; you have reduced yourself to a condition of stark ignorance. What is worse, some of you have become like the animals, indulging in lustful activities, not minding the evil consequences.
What has happened to you that you do not love one another, nor admonish one another, though you are brothers in Islam? There is discord among you because of your wrong desires, arising out of the corruption within you. If you are united in the cause of 'Deen' and affairs of 'Deen', your bonds of mutual relationship will be strengthened.
What has happened to you, that you counsel one another about affairs of this world, but do not do so about affairs of the Akhirah? You are incapable of admonishing those whom you love and do not give them good counsel about the affairs of the Hereafter. This is only because of your weak faith. If you had faith in the good and evil things of the Hereafter, like your belief in the good and evil things of this world, you would certainly give preference to the Akhirah. The Akhirah should have greater control over your affairs.
You may say that the needs of this world are immediate, while those of the Hereafter are remote. Just imagine how many activities there are, in this world, of which the fruits have to be reaped later. Still you toil and fret and struggle hard for them! For example, you work hard in the fields, for months together, hoping to reap crops in the end. Similarly, you take pains to plant trees in the garden, hoping to pick the fruit after years of hard labour and patient waiting. You have deteriorated, in matters of faith, so much that you do not care to gauge the level of your Imaan (faith) by doing things that would reveal it'.
'If you have any doubts about the revealed knowledge conveyed to us by Rasulullah Sallallaho alaihe wasallam, please come to us, so that we may show you the truth of this knowledge and make it abundantly clear to you. Come, we will show you the light by which you will be able to see, for yourself, that whatever Rasulullah Sallallaho alaihe wasallam said is absolutely true. You are no fools that we should regard you incapable of understanding it. For, you hold sound views about worldly affairs and act upon them most carefully. Then, what is wrong with you that you do not exercise wisdom, nor act with due care in affairs of the Akhirah.
What has happened to you? Why is it that you feel very happy over a paltry gain of this world and feel very sad over a little loss, to the extent that its effect is reflected in your faces. You complain of your 'sufferings', calling a little trouble a 'suffering' and hold meetings to console one another. But you are not grieved, nor feel sad, when you happen to miss an important religious requirement; your faces do not wear an _expression of sorrow.
When I see your indifference towards 'Deen', I feel inclined to think that Allah Ta'ala has forsaken you. You greet one another happily but everyone avoids saying anything which may be unpleasant, though true, to the other. He fears lest the other person should say to him something in return, which would displease him. So, you live amicably, keeping all dark thoughts to yourselves. Thus you have become corrupt from within though, outwardly, you seem to be enjoying life. And you seem to have all agreed not to think of death.
I wish Allah Ta'ala would grant me death and relieve me of sorrow on your account! And, I wish to join the company of those I love most dearly (meaning Rasulullah Sallallaho alaihe wasallam and the Sahabah Radhiallaho anhum). If they were alive, they would not have liked to associate with you, even for a short while. If there still remains an iota of good in you, take heed. For, I have told you what I think of you clearly and without hesitation, and I have spoken the truth. It is quite easy to achieve that which Allah Ta'ala has got in store for you (the boons of the Hereafter). And I seek help from Allah Ta'ala, both for you and myself'. "
Found via Alexandalus