Pillars of Islam are five and are also called as arkan-al-Islam or arkan ad-deen. Faith alone is not enough. It must be expressed and tested in action, i.e., the "five pillars of Islam", which are the manifestations of faith.
These are five basic acts in Islam, considered obligatory by every Muslim. These are summarized in the famous Hadith called as hadith E Jibreel, Sahih Al Bukhari Vol 1:7 and Sahih Al Muslim Vol 1:1 and 6.
Islam is both belief and laws, in which Allah and His Messenger have told us what is halal and what is haram, morals and good manners, acts of worship and how to interact with people, rights and duties, and scenes of the resurrection. When Allah completed this religion, He chose it to be the way of life for all of mankind until the Hour (Judgement Day) begins
Pillars of Islam
(1) The Creed ( Shahadah),
(2) Daily Prayers ( Salah ),
(3) Almsgiving ( Zakath ),
(4) Fasting during Ramadan (Sawm) and
(5) The Pilgrimage to Makkah (Hajj) at least once in a lifetime.
The Qur’aan presents them as a framework for worship and a sign of commitment to the faith . In some ahadith fasting in Ramadan is in fifth position and Hajj in fourth position.
First Pillar - Shahadah (Testimony or Creed)
The Shahadah , which is the basic creed of Islam that must be recited under oath with the specific statement: "Ashadu an la ilaha illa-llah, wa ashadu anna Muhammadur Rasulullahi", or "I bear witness that there is no Ilah(Any God) deserved to be worshipped but Allah (Glory be to Him), and I bear witness thatMuhammad is Allah’s Messenger." This testament is a foundation for all other beliefs and practices in Islam. The testimony or the creed consists of two parts ie ,
Tawheed (Allah’s Oneness)and Risalath (Prophet Muhammad’s Messengerhood). Non-Muslims wishing to revert to Islam are required to recite the creed.
The Importance of the Shahadah In Islam
To enter Islam, the Shahada plays an important role. By declaring the shahada, or testimony, is all one needs to enter Islam. It is the most important of all the five pillars of Islam. This little phrase is what separates Muslims from everyone else. Because those who state this phrase have declared their acknowledgment of Allah’s monotheism and Prophet Muhammad (May Allah honour Him and grant Him Peace) status. A person can revert to Islam by stating the Shahada with conviction.The person who accept this pledge vows that he will offer worship to the One and Only creator (Allah) and none else, and that he will lead his life, following the practice and example of Prophet Muhammad (May Allah honour Him and grant Him Peace).
It (la ilaha illa-llah) is the same message conveyed by Adam, Ibraheem (Abraham), Musa (Moses), ‘Eesa (Jesus) and finally to mankind until the Day of Resurrection by Prophet Muhammad (Peace and blessings of Allah be upon them All). This testimony is the key toParadise . But there is no key except that it has ridges. If you come with the key that has the right ridges, the door will be open for you. Otherwise, it will not open for you. In order to achieve Paradise through this testimony, one must fulfill certain conditions that constitute the “right ridges” for this key statement.
Is it Enough to "Say" Shahaadah lailaha Illallaah?
The Belief in the Oneness and Uniqueness of Allah (Glory be to Him) ( Tawheed) is not enough But believing Allah (Glory be to Him) by Muhammad’s (May Allah honour Him and grant Him Peace) way is very important for every Muslim who wants to enter Paradise , Qur'an.Surah A’le Imran 3: 31,32.
Second Pillar - Salah (Prayer)
Salah or Salat (Arabic: ????) is the second of the 5 Pillars of Islam. Allah (Glory be to Him) commands: “Verily, I am Allah. There is no god but I: So serve Me (only), and establish regular prayer for My remembrance", Qur’an.Surah Ta-ha 20:14 . In Islam, Salah is a compulsory act, must be performed five times a day. Salah is intended to focus the mind on Allah (Glory be to Him), and is seen as a personal communication with him that expresses gratitude and worship. Salah is compulsory but flexibility in the specifics is allowed depending on circumstances. The prayers are recited in the Arabic language, and consist of ayath from the Qur'aan .
A Masjid is a place of worship for Muslims, often refer to it by English name, masjid. "A person, who does not desist from bad and unjust deeds after offering prayers, strays away from Allah."It is the compulsory responsibility of every Muslim to offer Salah five times a day. The timings to be strictly adhered to fall before sunrise, during midday, evening, after sunset and at night. The Salah is to be performed after doing ritual ablutions which symbolizes purification of body and soul. It is certain that the life of a true Muslim who sincerely takes the vow of truth and offers prayer five times, meticulously standing with folded hands, bowing, prostrating and sitting, thus involving oneself in a conversation with Creator, will be freed of all wrongs. The only ayath which gives an indication of five times salah is mentioned in Qur’an.Surah Taha 20:130.
The five daily prayers are obligatory (Farz) on every Muslim (Both Male and Female). We cannot just abandon the Islamic prayers. The Salah are part of our identity as Muslims. In fact, Prophet Muhammad (May Allah honour Him and grant Him Peace) has stated: (The difference) between the believer and the disbeliever is the Salah.” For this reason, many Islamic scholars say that a person who deliberately abandons the Muslim prayers, and never makes them up, is not a Muslim.
Third Pillar - Zakath (Alms Giving)
"Zakath" (Arabic: ????? zakah"alms") is the third pillar of Islam. Zakat is one of the major religious duties in Islam. Literally, zakah means to "purify". It refers to the purification of a Muslim's wealth and soul. Wealth purification denotes the mobilization of assets for the purpose of financial growth and justified distribution. Purification of the soul implies freedom from hatred, jealousy, selfishness, uneasiness and greed. Such actions can go a long way in establishing a just and crime-free society. Other Qur'anic connotations include the purification of sin . Technically, zakah is a fixed proportion collected from the surplus wealth and earnings of a Muslim. It is then distributed to prescribed beneficiaries and for the welfare as well as the infrastructure of a Muslim society in general, the list of people to whom Zakath can be given is mentioned in the Qur’an.Surah Taubah 9:60 . This contribution is made payable by a Muslim once in every lunar year (Islamic Calendar/Hijri).
Any Muslim male or female who at the end of the Hijri year is in possession of the equivalent of 85 grams of gold or more in cash or 595 grams of pure silver. The Islamic Fiqh and Research Councils, as well as Jumhur (majority) of Ulama' recommend that gold be used as the basis for the calculation of Nisab. This minimum value is termed Nisab. A Muslimmust pay his or her zakah at the minimum rate of 2.5% on the total value of 85 grams of gold. Zakah has a deep humanitarian and social-political value. This religious act prevents the hoarding of wealth and advocates solidarity amongst Muslims because excessive wealth is distributed amongst the poor. The paying of zakah also helps purify one's soul and encourages a Muslim to have gratitude towards Allah’s bounties. "Of their wealth take alms, that so thou mightiest purify and sanctify them; and invoke Allah for them. Verily! Your invocations are a source of security for them, and Allah (Glory be to Him) is All-Hearer, All-Knower." Qur’an.Surah Taubah 9:103
On the Day when that (Al-Kanz: money, gold and silver, the Zakaah of which has not been paid) will be heated in the fire of Hell and with it will be branded their foreheads, their flanks, and their backs, (and it will be said unto them:) ‘This is the treasure which you hoarded for yourselves. Now taste of what you used to hoard’”
[al-Tawbah 9:34-35]
Concealing one’s zakaah is better than paying it openly in front of people, as Allaah says (interpretation of the meaning):
“If you disclose your Sadaqaat (almsgiving), it is well; but if you conceal them and give them to the poor, that is better for you. (Allaah) will expiate you some of your sins. And Allaah is Well-Acquainted with what you do [al-Baqarah 2:271]
Fourth Pillar - Saum (Fasting)
Fasting , (Arabic: ???? Sawm), in the month of RAMADHAAN or RAMZAN is one of the five pillars of Islam. It is FARZ upon every Muslim, male and female who is sane and mature. Almighty Allah (Glory be to Him) has promised great reward for those that Fast, whilst severe punishment is in store for those that do NOT fast in the month of Ramadhaan. Fasting has many physical, moral and social benefits. However, Allah (Glory be to Him) has made fasting compulsory so that we become pious, God fearing and God conscious. Fasting in ISLAM means to stay away from EATING, DRINKING and COHABITATION from Subha Sadiq (early dawn) to sunset with a Niyyat (Intention at Heart)of fasting (ROZAH), Qur’an.Surah Baqrah 2:183 - 185 . Month of fasting ends with a daylong celebration known as Eid ul Fitr or the Festival Day.
The command of Fasting is given in Qur’an, as Allah (Glory be to Him) says: "O you who believe! Fasting is prescribed for you as it was prescribed for those before you, that you may become Tattaquun (God-fearing).", Qur’an.Surah Baqra 2:183 . "Ramadhaan is the (month) in which was sent down the Qur’aan , as a guide to mankind, also clear (signs) for guidance and judgement (between right and wrong). So every one of you who is present (at his home) during that month should spent it in fasting." Qur’an.Surah Baqra 2:185 . Ramadhaan, is the month in which the Qur’an was first revealed on the night of Lailat al-Qadr, Qur’an.Surah Qadr 97:1 .
The Prophet Muhammad (May Allah honour Him and grant Him Peace) said: Whoever fasts during Ramadan with faith and seeking his reward from Allah (Glory be to Him) will have his past sins forgiven and whoever prays during the night of Qadr in Ramzan with faith and seeking his reward from Allah (Glory be to Him) will have his past sins forgiven. Sahih Al Bukhari Vol 3:125
Fifth Pillar - Hajj (Pilgrimage)
The Hajj (Arabic: ???) is the pilgrimage to Makkah, Saudi Arabia. It is the largest pilgrimage in the world, and is the fifth pillar of Islam, a religious duty that must be carried out at least once in their lifetime by every able-bodied Muslim who can afford to do so. The Hajj is a demonstration of the solidarity of the Muslim people, and their submission to Allah (Glory be to Him). The pilgrimage occurs from the 8th to 13th day of Dhu al-Hijjah, the 12th and last month of the Islamic calendar. Every year millions of Muslims, from different countries, travel to Makkah with the purpose of undertaking the great obligation of Hajj. It is an exemplary example of equality and unity when the pilgrims gather together for Hajj. Muslims who belong to different nations, cultures, social and economical status are all dressed in two pieces of unsown cloth. All perform the same rites. There is no difference of rich and poor, all stand in front of their Lord in submission and humility. Hajj is a symbol of submission to Allah (Glory be to Him) and Muslim Unity.
Linguistically, Hajj means, 'He prepared, or betook himself, to or towards a person or towards an object of reverence, veneration, respect or honor.” In the Sharee'ah, Hajj means a specific journey to Makkah during the designated month of Dhul-Hijjah, for the performance of Hajj as an act of worship to Allah (Glory be to Him): “The Hajj is (in) the well-known month (12th month of the Islamic calendar called Dhulhijjah). So whosoever intends to perform Hajj therein by assuming Ihram, then he should not have sexual relations (with his wife), nor commit sins, nor dispute unjustly during the Hajj. And whatever you do, (be sure) Allah (Glory be to Him) knows it.” Qur’an.Surah Baqarah 2: 197. “Hajj to the House is a duty that mankind owes to Allah (Glory be to Him)for those who can afford the journey”was revealed.
Qur’an.Surah Ale Imran 3: 97. Certain conditions have to be fulfilled before Hajj becomes compulsory upon an individual. These can be enumerated as follows: (a) Islam, (b) soundness of mind, (c) puberty and (d) capability
If the Muslim does Hajj correctly, in the manner prescribed and sincerely for the sake of Allaah, it will be an expiation for his sins. The Prophet (peace and blessings of Allaah be upon him) said: “Whoever does Hajj for the sake of Allah, and does not have sexual relations or commit sins, will come back like the day his mother bore him.” Sahih Al Bukhaari, 1819 (Vol 3:45)
Conclusion
Allah (Glory be to Him). says in the Qur’an: "And whoever seeks a religion other than Islam, it will never be accepted of him, and in the Hereafter he will be one of the losers." Qur’an.A’le ‘Imran 3:85
References
http://islamqa.info/en/ref/13569