Islamic Practice
The bare minimum that a Muslim must do and believe in order to rest assured of his or her salvation is quite simple, although the faith and practice of many Muslims may often be complex and elaborate, reminding students of the detailed and scrupulous observance of Rabbinic law in Orthodox Judaism and the precise doctrinal formulations of Catholicism.
Basic, rudimentary Islam is clearly stated in the following "sound" (sahih) hadith:
A Bedouin came to the Prophet and said, "Tell me of a deed such that if I were to do it, I would enter Paradise (as a result)." The Prophet said, "Worship God (Allah) without worshiping anything along with Him, offer the (five daily) prescribed prayers, pay the compulsory alms(zakat), and fast the month of Ramadan." The Bedouin said, "(I swear) by Him in whose hands my life is, I will not do more than this." When he (the Bedouin) left, the Prophet said, "Whoever would like to see a man of Paradise should look at this man." Narrated by Abu Hurayrah in the Sahih of Bukhari, Volume 2, p. 272-73, book 23, #480.

Although the hadith noted above indicates four practices (worship of God alone, prayer, almsgiving, and fasting), the core of Islamic practice (which is the concrete or outward manifestation of the inward attitude of surrender to God) is expressed in the well-attested hadith, "Islam is based upon five [practices]..." which are also called the "five pillars." (This is also confirmed in the well-attested and well-known hadith involving Gabriel (link fixed 17 August 2005).) These five practices are as follows:

shahada,bearing witness that there is nothing worthy of worship but God and that Muhammad is God's messenger;
salat, performing the prescribed Islamic prayer;
zakat, almsgiving of a 2 1/2 % tax on one's asests;
sawm, fasting from sunrise to sunset during the month of Ramadan; and
hajj, performing the pilgrimage to Mecca.