Islam is based on five pillars, namely:

1. Shahaadah - the testimony. When you bear witness that there is no God but Allah, and Muhammad (May Allah's Peace and Blessings be upon him). We completely submit to Allah (Subhanahu wa Ta'alaa), and from then onwards, we must obey Allah (SWT) and do everything in order to please Him. For more on Shahaadah, please visit http://www.viewislam.com/pillars/pillar1.htm
2. Salaah - the five daily prayers. We Muslims pray to Allah five times a day. When we pray to Allah, we wash away our sins. However, before praying, we must make sure that we are both spiritually and physically clean, by doing wudhoo (ablution). Once the Messenger of Allah (SAWS) asked his companions that if one of them had a river flowing in front of their houses and they bathed in it, five times a day, would any dirt be left on thier bodies? He received an answer that no dirt would be left on sucha body. The Prohpet further said, that such is the case of the person who prays to Allah daily, five times. In addition, when we pray to Allah, we strengthen our relationship with Allah. The rewards for establishing the prayers include tranquility and happiness that are felt in the heart. Prayer also leads one to abandoning evil deeds and behavior. For more on Salaah, please visit http://www.viewislam.com/pillars/pillar2.htm
3. Paying Zakat is worshipping Allah by paying the amount of charity obligated on the ones who have enough money or possessions that require paying Zakat. Zakat is an obligatory form of charity on savings. It is not an income tax, but a savings tax. Its major recipients are the working poor, who cannot meet all of their needs without some additional help, and the destitute, who cannot even meet their basic needs. For more on zakat, please visit http://www.viewislam.com/pillars/pillar4.htm
4. Ramadaan is the month in which we neither eat nor drink from dawn to dusk. Before we start out fast, it is better that we eat just before dawn, and when breaking our fast, we eat right after dusk. It is preferable that we break our fast with dates or water if dates are not available. For more on Ramadaan, please visit http://www.viewislam.com/pillars/pillar31.htm
5. Performing Haji (pilgrimage to Makkah) is worshipping Allah by visiting the Holy House to perform the rituals of Hajj. Hajj trains the souls to spend time and physical effort, seeking to obey Allah. This is why Hajj is considered a type of Jihad (struggle). These fruits of performing the pillars of Islam, along with many others we did not mention, make the Muslim nation pure and clean. They lead the nation to preserving the religion of Truth and dealing with the creation in the best manners of justice and truthfulness. All other acts of the religion depend on how well these pillars are preserved. The Ummah (Muslim nation) can reach success as long as its members preserve the religion. This Ummah will not reach the desired success as long as the religion is not fully respected and preserved. Whoever wants to be certain of the above mentioned facts, let him read the following Ayat (verses), (And if the people of the towns had believed and had piety, certainly, We should have opened for them blessings from the heaven and the earth, but they belied (the Messengers). So We took them (with punishment) for what they used to earn (of evil deeds). Did the people of the towns then feel secure against the coming of Our punishment by night while they were 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 plot of Allah? None feels secure form the plot of Allah except the people who are lost) [7:96-99]. Let him also read the history of previous nations, which gives valuable lessons for whoever is in possession of a mind that comprehends and is rightly guided. This history is a light for those whose hearts are not blocked from the truth. All our dependence is on Allah. For more on Hajj, please visit http://www.viewislam.com/pillars/pillar5.htm