The Three fundamental Islamic beliefs are:
Tawhid - The Oneness of Allah (subhanahu wa ta’ala)
Risalah – Prophethood
Akhira - Life after death
Tawhid, is the most important Islamic belief. Everything in existence originates from the one and only Creator, who is the Sustainer and sole Source of Guidance. This belief should govern all aspects of human life. Recognition of this fundamental truth brings a unified view of life which rejects any division into religious and secular.
Allah (subhanahu wa ta’ala) is the sole source of Power and Authority and is to be worshipped and obeyed. He has no partner; Tawhid is pure monotheism. Allah (subhanahu wa ta’ala) is not born, and He has no dependants. Human beings are His subjects. He is the One; He is Eternal. He is First and the Last; and there is none like Him.
Belief in Tawhid brings total change to a Muslim's life. It makes him bow down only to Allah, Who sees all of his actions. He must work to establish the laws of Allah in all areas of life in order to gain His pleasure.
Risalah, means Prophethood or Messengership. Allah (subhanahu wa ta’ala) has not left man without Guidance for the conduct of his life since the creation of the first man. Allah (subhanahu wa ta’ala) has revealed His guidance to mankind through His Prophets. Prophets who received books from Allah are called Messengers. All the Prophets and Messengers came with the same message; they urged the people of their time to obey and worship Allah (subhanahu wa ta’ala) alone and none other. Whenever the teachings of a Prophet were distorted by people, Allah (subhanahu wa ta’ala) sent another Prophet to bring them back to the Straight Path (Sirat ul Mustaqim). The chain of Risalah began with Adam, included Noah, Abraham, Ishmael, Isaac, Lot, Jacob, Joseph, Moses, David, Jesus, and ended with Prophet Muhammad (peace be upon them all). Prophet Muhammad (peace be upon him) is the final Messenger of Allah to mankind.
The revealed books from Allah (subhanahu wa ta’ala) are the Torah (Tawrat), the Psalms (Zabur), the Gospel (Injeel) and the Quran. The Quran, which was revealed to the Prophet Muhammad (peace be upon him) is the final book of Guidance.
Akhira, means life after death. Belief in Akhira has profound impact on the life of a believer. We are all accountable to Allah (subhanahu wa ta’ala) on the day of Judgement, when we will be judged according to how we lived our lives. A person who obeys and worships Allah (subhanahu wa ta’ala) will be rewarded with a place of happiness in Paradise; the person who does not will be sent to Hell, a place of punishment and suffering.
Allah (subhanahu wa ta’ala) is aware of our every thought and innermost intention; angels are recording all our actions. If we always keep in mind that we will be judged by our actions, we will try to make sure that we act according to the Will of Allah (subhanahu wa ta’ala).