Arkaan ul-Islaam are its basic foundation upon which it is established; they are five, mentioned in the narration by Ibn Umar (radhi-Allaahu ‘anhu) in which the Prophet (sal-Allaahu ‘alayhe wa-sallam) said:
“Islaam is raised on five (pillars): To establish His Tawheed [and in other narration “The [i]Shahadah (testimony) that La ilaaha illal laah (none has the right to be worshipped but Allaah) and that Muhammad is Allaah’s slave and Messenger], establishment of prayers, payment of Zakaat, the fast of Ramadaan, and Pilgrimage (to Makkah).[/i] A person said (to the narrator) (which of the two precedes the other) - Pilgrimage or the fasts of Ramadaan? Upon this he (the narrator) replied: No (it is not the Pilgrimage first) but the fasts of Ramadaan precede the Pilgrimage, this is how I have heard it from Allaah’s Messenger.” 
First: The Shahadah of:
La ilaaha illal laah, Muhammad Rassoulul laah
Is the decisive belief expressed on the tongue as though one sees with his own eyes the certainty of his firm conviction. The fact that the Shahadah has been made as a single pillar despite the multiplicity in what is being attested, is because of either of the following (reasons):
- The Messenger (sal-Allaahu ‘alayhe wa-sallam) is a bearer (of news) about Allaah (Ta’aalaa). Attesting, therefore, that he (sal-Allaahu ‘alayhe wa-sallam) is a true slave of Allaah and a bearer of the Message (of Islaam) is an integral part of the meaning of Shahadah (La ilaaha illal laah), or
- That the two testimonies La ilaaha illal laah, and Muhammad Rassoulul laah, are the (required) bases for the rightness of deeds and of their acceptance, since both, the validity and acceptance of deeds, cannot be achieved without Al-Ikhlaas to Allaah (sincere devotion of intentions to Allaah alone) and Mutaba’ah (following) of Rassoulul laah (sal-Allaahu ‘alayhe wa-sallam). It is through Al-Ikhlass that the Shahadah of La ilaaha illal laah is realized, while through Al-Mutaba’ah of Rasooul-Allaah, the Shahadah that Muhammad is Allaah’s slave and Messengers is manifested.
Some of the Benefits attained by the declaration of the great Shahadah include the liberation of the heart and soul from slavery to the created, and from following paths other than the Messengers’ path.
Second: Regarding the Establishing of Prayers: it is worshipping Allaah by performing it in the right and perfect manner  and on its prescribed times. Some of its Benefits include the openness of the chest, contentment and joy, and restrainment from committing sins and wrong-doings.
Third: The Giving of Zakaat: is devoting worship to Allaah by offering the obligatory prescribed amount of charity deducted from the wealth upon which Zakaat is due. Some of its Benefits are: purifying the self from immoral characteristics like misery, and fulfilling the needs of Islaam and Muslims.
Fourth: Fasting: it is devoting worship to Allaah by refraining from everything known to nullify the fast during the days of the month of Ramadaan.
Fasting coaches the self to endure the relinquishment of what it is like seeking to gain the pleasure of Allaah.
Fifth: The Hajj to The House of Allaah: is worshipping Allaah by going to the Sacred House (Al-Ka’bah) to execute the rites of Hajj.
Some of its Benefits include: the training of the self to expend physical and financial sacrifices in obedience to Allaah (Ta’aalaa). This is the reason why Hajj is considered as one kind of Jihad in the cause of Allaah (Ta’aalaa).
The Benefits that we have mentioned above regarding the basics of Islaam, and others which we have not mentioned, makes of this Ummah a virtuous and purified Islaamic Nation adhering to Allaah through the Deen of Truth, and treats the created with justice and truthfulness. This (conclusion) holds true because the right adherence to the rest of the Islaamic Laws depends upon the proper practicability of the above basics.
The status of the Ummah will thrive and prosper as long as it properly adheres to the matters of its Deen. The degree of its prosperity that may escape is proportional to the degree of abandonment of good adherence to matters of its Deen. Whoever seeks an evidence for this, let him read the saying of Allaah (Ta’aalaa):
“And if the people of the towns had believed and had the Taqwa (piety, fear of Allaah), certainly, We should have opened for them the blessings from the heaven and the earth, but they belied (the Messengers). So We took them (with punishment) for what they used to earn (polytheism and crime, etc.). Did the people of the towns then feel secure against the coming of Our Punishment by night while they are asleep? Or, did the people of the towns then feel secure against the coming of Our Punishment in the forenoon while they play? Did they then feel secure against the Plan of Allaah. None feels secure from the Plan of Allaah except the people who are lost.” [Qur’aan 7:96:99]
Let him also examine the history of those who preceded because history is a lesson for people of thought, and an insight for anyone free from any obstructing barrier to his heart. And it is Allaah alone whose Help can be sought.
 Agreed upon hadeeth: The text is from Saheeh Muslim.
 As detailed by the Prophet Muhammad (sal-Allaahu ‘alayhe wa-Sallam) in his authentic Sunnah. See for example an excellent collection of the narration’s describing the Prophet’s Prayer in Shaykh Naasir-ud-Deen Al-Albaanee’s book: “The Prophet’s Prayer”. [TN]