Islam has explicitly stated that religion, to Allah, is one and the same, that the prophets sent by Allah to mankind complement each other, beginning with Adam, peace and blessings of Allah be upon him, up to Muhammad peace and blessings of Allah be upon him, and that the messages of those prophets and messengers are in agreement about calling to the following:
Belief in the Oneness of Allah, glory to Him, with no associates, equals or likes.

Belief in Allah, His angels, books, messengers, and the Hereafter.

Good manners and refinement of the human self by guiding it to the way of reform and happiness in this life and the Hereafter.

Direct worship of Almighty Allah without the intervention of any intermediaries in worship.

The establishment of peace and love in human societies. Allah, glory to Him, says: “He has ordained for you the same religion which He commended unto Noah, and that which We have revealed to you (O Muhammad), and that which we commended unto Abraham and Moses and Jesus saying: Establish the religion, and be not divided therein. Dreadful for the idolaters is that unto which you call them.” (The Qur’aan, Chapter Ash-Shura, 42:13)

The Islamic Religion is the final and concluding Shari’ah (Law) or way of life; there is no (other) religion to follow. Its primal constitution, which is the Glorious Qur’aan, is permanent and preserved and will remain up to the end of this world and living things as indicated in the Qur’an: “Lo! We, even We, have revealed the Reminder (Qur’aan) and Lo! We verily are its Guardian.” (The Qur’aan, Chapter An-Nahl, 15:9)

Allah’s Messenger, peace and blessings of Allah be upon him, is the last of messengers. There is no messenger or prophet after him. Prophet Muhammad peace and blessings of Allah be upon him said: “My similitude in comparison with the other prophets before me, is that of a man who has built a house nicely and beautifully, except for a place of one brick in a corner. The people go about it and wonder at its beauty, but say: ‘Would that this brick be put in its place!’ So I am that brick, and I am the last of the prophets.” (Bukhari)
Issa (Jesus the son of Mary), however, will come down in the last days of this world to fill the world with justice as it was filled with oppression and injustice. He will not be sent with a new religion of Muhammad, peace and blessings of Allah be upon him, as indicated by the last Prophet peace and blessings of Allah be upon him: “The son of Mariam (i.e., Jesus son of Mary) will soon descend amongst you as a Just Ruler: he will break the Cross, kill the pigs, put an end to jisya (i.e. taxation taken from rich non-Muslims for defending them in case they do not participate in defense of the country), and money will be in abundance so that nobody will accept it.” (Imam Ahmad and Bukhari) To accept this universality, Muslims have been ordered to convey the Message of Islam and present it to mankind as stated in the Qur’an: “Thus We have appointed you a middle nation, that you may be witnesses over mankind, and that Messenger may be a witness over you...” (The Qur’aan, Chapter Al-Baqarah, 2:143)
Islam has completed and brought to perfection former religious ways of life which were spiritual in their roots. They addressed the human self and called to its purification, but did not take care or regulate worldly and living affairs, in contrast with Islam, which completed and regulated all aspects of life. It has covered all religious and worldly affairs, as will be made clear later. Allah has stated: “…This day have I perfected your religion for you and completed My favor unto you, and have chosen for you Islam as your religion...” (The Qur’aan, Chapter Al-Maidah, 5:3)

Allah, glory to Him, does not accept that devotion should be directed to other than Him or that anyone or anything should be worshipped as an intermediary between people and their Rabb (Cherisher and Sustainer). He said: “And who so seeks a religion other than Islam, it will never be accepted from him, and he will be a loser in the Hereafter.” (The Qur’aan, Chapter Al-Imran, 3:85)
Islam is a universal message addressed to the whole humanity without exception everywhere and at all times, to people and jinn, Arabs and non-Arabs, blacks and whites, male and female, poor and rich. Allah, says:“And We have not sent You (O Muhammad) save as a bringer of good tidings and a Warner unto all mankind...” (The Qur’aan, Chapter Saba, 34:28) It is a universal religion: not revealed or sent exclusively to one race, class or nation. It unites all mankind, not on basis of color, language, region, or lineage, but on basis of a specific creed that combines and unifies them all. Everyone who believes in Allah as his Rabb, in Islam as his religion, and in Muhammad, peace and blessings of Allah be upon him, as his Messenger, has come under the flag of Islam. Allah, glory to Him, says: “Say (O Muhammad): 'O mankind! Lo! I am the messenger of Allah to you all...'” (The Qur’aan, Chapter Al-A’raf, 7:158) Allah’s Messenger peace and blessings of Allah be upon him, said: “I have been conferred upon five (things) which were not granted to anyone before me (and these are):

1- I have been supported with awe (i.e. with fear that haunted the minds and hearts of the enemies of Islam) from the distance of one month travel.
2- The earth has been made a place of worship and purification for me, so whenever the time of prayer come for any one of my Ummah (followers) he should pray wherever he is.

3- The spoils of war have been made lawful for me.
4- I have been granted intercession. And
5- Every messenger was sent particularly to his own people, whereas I have been sent to all humankind.” (Bukhari and Muslim) This does not suggest lack of belief in earlier messengers or scriptures: Jesus perfected the religion of Moses, and Muhammad perfected the religion of Jesus, and Muhammad closed the chain of prophets and messengers; peace be upon them all. It is part of the perfect faith of a Muslim to believe in all revealed books and prophets before Prophet Muhammad, and anyone who does believe in all, or any, of them will be a non-Muslim. This is clear from the Prophet’s statement when he was asked about belief he peace and blessings of Allah be upon him, said: “It is to believe in Allah, His angels, books, messengers, the Hereafter and divine destiny of Decree to good and evil.” (Muslim)

Islam is distinguished for its divine laws and instructions, which are not man-made and so they are free from defects and faults and from the impact of surrounding effects such as culture, heritage and environment. This is evident in reality: human laws and legislation are changeable - what fits one community may not fit another. For example laws and regulations of a capitalist society do not go well with the conditions of a socialist one, and vice versa. Each legislator would choose what is in agreement with his aspirations and inclinations. In addition, such laws are unstable, for a more informed and knowledgeable person may object, rescind or add to the work of an earlier legislator. Islamic law, however, is made by Allah. Its Legislator is the Creator of the whole universe and all beings. He is also Omniscient and All-Aware of all that is suitable for them and makes good all their affairs. Humans, however high their rank is, have no right to object to or change any divine law, whether by increase or decrease or choosing what agrees with their desires and whims. Allah, glory to him said: “And it becomes not a believing man or a believing woman, when Allah and His Messenger have decided an affair (for them), that they should (after that) claim any say affair.” (The Qur’aan, Chapter Al-Ahzab, 33:36), “It is a judgement to a people of the time of (pagan) ignorance that they are seeking? Who is better than Allah for judgement to a people who have certainty (in their belief)?” (The Qur’aan, Chapter Al-Maidah, 5:50)

Islam has introduced absolute, comprehensive and perfect rules and fundamentals that are not subject to change and revision with the elapse of time. It, nevertheless, left particulars and details that are not explicitly stated in the Qur’aan and Sunnah for responsible, authoritative and erudite scholars everywhere at any time to exert their effort to derive and infer verdicts and provisions that are in the public interest and suit the prevailing conditions in human societies at various times and environments. This Ijtihad, or religious reasoning and investigation, is not to be controlled by prejudices and desires but aims to reach truths that are of use to humankind, so that Islam should keep up with, and adapt its detailed regulations with every age and society. The role of the Muslim government is to bring those divine laws and rules into force and enforce them on everyone, with no distinction between the rich and the poor, the noble and the lowly, the president or chief and his subjects, the whites and the blacks, in all are alike and equal before the law.
Bukhari and Muslim narrated, on the authority of A’isha, may Allah be pleased with her, that Quraysh tribes were concerned about the case of a Makhzumi woman who was accused of theft. They said: Who will plead on her behalf with Allah’s Messenger, peace and blessings of Allah be upon him? Some of them suggested: Who other than Usamah ibn Zaid, whom the Prophet loves very much, can do so? As such, Usamah represented her case to the Holy Prophet, who told him: Do you intercede in the matter of a grave crime involving punishment prescribed by Allah? So saying, he got up and delivered an address in which he said: “The people who preceded you were destroyed because they use to let off a rich (influential) person if he committed theft, and to punish a weak person who committed the same crime. By Allah, If Fatimah, daughter of Muhammad, had committed this offense I would have cut off her hand.”

Islam is distinguished by the fact that its text and sources are original, genuine and intact (with no addition or omission). They are of permanent, eternal authenticity and validity up till the Day of Resurrection. Basic sources of Islamic Shari’ah are the Holy Qur’aan and the Noble Sunnah (the traditions and teachings of Prophet Muhammad, peace and blessings of Allah be upon him). Allah, Exalted be He, has undertaken to preserve the Qur’an He said: “Lo! We, even We, have revealed the Reminder (i.e. the Qur’aan) and Lo! We verily are its Guardian.” (The Qur’aan, Chapter An-Nahl, 15:9) Since its revelation onto Muhammad, peace and blessings of Allah be upon him, up to the present, the Qur’aan had not undergone any change, distortion, increase or decrease. Many attempts have been made from the side of those who plotted against Islam to add or delete one word, but their efforts ended in failure. That is because it was preserved in books and minds as it was recited in prayer or as a form of worship. According to the Gracious Prophet peace and blessings of Allah be upon him, he said: “Whoever recites one letter from the Holy Qur’aan will get one good deed in recompense will be equal to ten good deeds. I do not say that ‘Alif Lam Meem’ (i.e. A,L,M) a letter, but A is a letter, L is a letter and M is a letter (i.e. it is equal to 3 letters).” (Tirmidhi) The Gracious peace and blessings of Allah be upon him, also said: “The best among you are those who have learnt the Qur’aan and taught it (to others).” (Bukhari) Therefore, Muslims hastened earnestly to teach the Holy Qur’an.
Many Western scholars admitted the excellence of the Qur’aan and its influence on human thought and sciences. Of such scholars there is Margoliouth[1], who was known for his prejudice against Islam, yet the greatness of the Qur’aan did not deter him from telling the truth when he pointed out that: “Researchers are all agreed that the Qur’aan occupied an outstanding rank among the dignified religious scriptures that made history, though the latest of them in revelation. It has surpassed all in its marvelous impact on man. It has created a new human thought and established a unique moral school.”
According to Jean Melia[2]: “It is a must to discard the pretension of some French philosophizers. The Qur’aan should be recited slowly and deliberately. It has nothing of the charges of opponents that it preaches bigotry. Islam is a heavenly revealed religion, a religion of love, affection and honor, and the most tolerant of faiths.”

Hart Wighischfield[3] held that: “One need not feel surprised if it is said that the Qur’aan is the source of sciences: All that the Qur’aan has talked about, such as the earth, human life, trade and craft, was the subject-matter of study by scholars and commentators who shed light thereon in their books and commentaries on the Qur’aan. This opened up a broad latitude of research and reflection which paved the way for the advancement of science with Muslims. Its influence was not limited to Arabs. However, it caused Jewish philosophers to follow in the steps of Arabs in metaphysical questions of religion. It is needless to mention the benefits that the Christian theology has derived from Arab research in theology.”
Likewise, the Prophet’s Sunnah (traditions, acts and confirmations) that belong, through an authentic chain of transmitters, to the Holy Prophet Muhammad peace and blessings of Allah be upon him, the second source of the Islamic Law and exponent of the Holy Qur’aan and its verdicts, has been preserved from abuse, invention and interpolation, through reliable chains of transmitters known for their integrity and soundness of memory. Such transmitters were upright scholars who devoted their lives to the study of Allah’s Messenger’s Ahadith…As such, they sifted all traditions (Ahadith, plural of Hadith) narrated from the Prophet and accepted only authentic ones, so they reached us pure and free from false narration. If one desires to know the way of Sunnah preservation, he can refer to books on Hadith Science that was established to serve the Holy Prophet’s Ahadith, so that he may make sure about the certainty and authenticity of the Prophets’ traditions we have received.

Islam considers all people as equal with regards to their origin and birth, both male and female. Allah, glory to Him, first created Adam, the father of all mankind, and created from him, his wife Eve - the mother of mankind and made them the origin of human offspring. The Qur’an declares human equality as to their origin: “O mankind! Be careful of your duty to your Rabb, Who created you from a single soul and from it created its mate and from them twain has spread abroad a multitude of men and women. Be careful of your duty toward Allah in Whom you claim (your rights) of one another and toward the wombs (that bear you, i.e., kinship)…” (The Qur’aan, Chapter An-Nisa’a, 4:1)

Prophet Muhammad peace and blessings of Allah be upon him, said: “People are the children of Adam and Adam is (created) of dust.” (Imam Ahmad) The people who are existing or will exist on earth, are of Adam’s progeny. They began to have one religion and one language; but being big in number, they spread throughout the earth. This inevitably led to difference of color and nature (as an inevitable result of environmental impact). This entailed different ways of thinking and living and different beliefs. The Qur’an states: “Mankind were but one community, then they differed...” (The Qur’aan, Chapter Yunus, 10:19)

Islamic instructions place man, regardless of his race, color, tongue, religion and homeland, on equal terms with his brethren, all equal before Allah. However, differences and conflict arise among them in as much as they are close to, or far from, compliance with Allah’s Law and way of life. The Qur’aan states in this connection: “O mankind! Lo! We have created you male and female, and have made you nations and tribes that you may know one another. Lo! The noblest of you in the sight of Allah, is the best in conduct...” (The Qur’aan, Chapter Al-Hujarat, 49:13) Based on this equality confirmed by Islam, all people are equal in freedom in the sight of Islamic Law. This slogan was launched by Caliph Omar Ibn Al-Khattab fourteen centuries ago when he said: “When did you enslaved people whose mothers had borne them free.”