He (the inquirer) said: You have told the truth. He (the inquirer) again said: Inform me about al-Ihsan (performance of good deeds). He (the Holy Prophet) said: That you worship Allah as if you are seeing Him, for though you don't see Him, He, verily, sees you. He (the enquirer) again said: Inform me about the hour (of the Doom). He (the Holy Prophet) remarked: One who is asked knows no more than the one who is inquiring (about it). He (the inquirer) said: Tell me some of its indications. He (the Holy Prophet) said: That the slave-girl will give birth to her mistress and master, that you will find barefooted, destitute goat-herds vying with one another in the construction of magnificent buildings. He (the narrator, Umar ibn al-Khattab) said: Then he (the inquirer) went on his way but I stayed with him (the Holy Prophet) for a long while. He then, said to me: Umar, do you know who this inquirer was? I replied: Allah and His Prophet knows best. He (the Holy Prophet) remarked: He was Gibreel (Peace be upon him). He came to you in order to instruct you in matters of religion.  
The Deen entirely includes in this famous Hadith. The out come of this conversation is the prominent three factors of Islamic Shareea’th. Firstly, a believer needs the Iman. The actions rooted not in belief are not acceptable. Secondly, a believer needs external doings like the Prayer, Hajj, charity and so on. Marriage, trade, social-relations and such matters are its peripheral factors. Ihsan is the very soul of all these actions. For, it can be made out from the above Hadith. The entity of worship is to do ibadah as you see the Almighty. If you can’t be so it is necessary to remember that the God sees you. The worship, which is not like this, is a mere external expression.
The relation between Ibadah and Ihsan is like that between body and soul. The soul is inevitable for the existence of the body. If the soul abstains from the body then the body will be destroyed.
In nutshell, the real Islam is the accumulation of three factors mentioned above. Each one related to one another. Any one of them cannot exist without another. The first stipulation of the prayer is the belief. That is why; the prayer of non believer is not acceptable. As like as, it is punishable and that to pray for showing others. So that, the belief, the action and the self refinement should be fit together in the prayer. Imam Malik (May Allah Mercy upon him) says: “if anyone becomes Sufi without jurisprudence he might be a skeptic. As like, if anyone becomes jurisprudent without thasavuf he might be a miscreant. The one who possessed these two is the real scholar” (Ieqadh page 6).
The former scholars handle the Fiqh and the Thasawwuf equally. When Islamic rules and courts increased in number then the rulers needed for the jurisprudence much. Accordingly, so many scholars turned their attention towards this branch and tried to be past masters on it. Some scholars who didn’t have any interest in state maters turned to Thasawwuf. They claim for spiritual matters and pure minds. In fact, here the Fiqh and Thaswwuf were known as two separate branches of Islamic knowledge.
The jurists listened only in their filed while Sufis in spiritual matters. They each tried to make their field flourished. Consequently, the Fiqh and Thasawwuf some times diverted into two ways. It affected the Islamic shareea’. When some polluted minds tried to handle the Fiqh they have even get out from the realm of Islam. Ibnu Hazm, the author of Mua’lla, is an example. When he strived to show the power of his knowledge, losing spiritual nobility he failed in finding truth. Besides, it is a sheer example before us that some followers of the Sufi orders went astray as they abandoned the Fiqh.
Imam Gazzali (May Allah Mercy upon him) has prevented this astray with his world famous book Ihya Uloomudeen. This book handles Fiqh and Thasawwuf more justly. It shot in to fame by weaving iman, ihsan and islam in a string.  The Keralite Imam Zainudin Makhdoom (May Allah Mercy upon him) in his Murshid and others followed the same way of Gazzali (R). The Hujjathul Baligha of Shah Valiyyullah is the best example for it.
The enjoyment of Sufism cannot be expressed in words. The above mentioned Hadith is clear evident for it. The Prophet (PBH) said the Ihsan is to worship the lord as you see. But in fact we don’t the suitable eyes for seeing the Almighty. Then how can we see Him? So it is very clear that here the intention is spiritual vision. It is a sort of highest enjoyment and can’t be depicted in words as we cannot explain the enjoyment of sexual intercourse to him who doesn’t have the experience. We are feeble to depict it in words.
The real spiritual enjoyment comes from the genuine worship. It can be enjoyed by any one. This is the ultimate intention of the worship of a believer. One may lose this enjoyment as only because of the illness in his worship. The intention of Sufism is to correct this illness.
On the basis of Qur’an and Sunnah, the spiritual scholars explained elaborately the stages of Mukashafa (Spiritual vision) in their books. As an example, the first one of the stages is Zuhd. It means that to make the mind abstained from family, friends, tribes and wealth. Here also, the Prophet (PBH) is our role model. Before the six months of his prophethood, he stayed alone in the cave of Hira. After wards, the message started to send down.
He who possessed all the stages gets the experience of Kashf. He can see many oracles not be seen by his five senses. Anybody can not reach this position but only hard practitioner can do this with the help of the Almighty. Once, the Prophet (PBH) said about the dream of a normal believer that it is one among the 46th parts of Vhy. Then the dream of a real believer might be one among the kinds of Kashf.
The one who got the Kashf can understand every spiritual and universal fact. Before the Kashf, he had mere a belief. But after the Kashf he becomes able to see everything whether it is things or not. He can see the matters other than things only through the suitable figures. Once, the Companions saw the Prophet (PBH) trying to take something during his prayer. The Prophet (PBH) said when they asked him about it: “in my prayer, the heaven was shown between me and my Qibla. At that time, I wanted to take a bundle of grapes from it. Afterwards, I avoided my intention”.
The Prophet (PBH) once said: “the Almighty created the brain, when He asked it to come forward it came in front and to come back it went back.”