All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Islam consists of clear evidence that proves its authenticity and that it is the true religion and that what Prophet Muhammad brought to humanity was the truth and nothing but the truth.
First, Islam is the religion of Fitrah (natural predispositions); the religion that suits the natural predispositions of human beings.
It calls for the worshipping of Allaah alone, because people should not humiliate themselves or submit themselves to any creature. By this, Islam has freed humanity from worshipping creatures and called to worship the Creator of those creatures instead. Thus Islam frees people from enslavement to other than the Creator.
Second, Islam is accepted by rational and sound minds, which is satisfied with the fact that there is only One Creator of this universe. Had there been another creator, there would have been disputes of supremacy which would have resulted in the destruction of the universe. In fact, the integrity of the system of the universe is evidence that only one God is responsible for it.
Third, Islam is a moderate religion that rejects all kinds of extremism. It takes care of both the soul and the body. It does not give preference to one of them over the other.
Fourth, Islam is a comprehensive religion in its rulings and covers all aspects of life; social, economical, spiritual and political. All these fields and more are given great importance in Islam.
Fifth, Quran, which is the main source of Islamic rulings, is preserved from any changes. It has not undergone any changes and remained in its original form since it was revealed. One of the means of preserving it is the fact that it is easily be memorized by the young, the old, males and females.
Sixth, modern science has discovered scientific facts that match the facts that were revealed in Quran and Sunnah (the tradition of Prophet Muhammad ) such as genetics, astrology, biology…etc.
After Islam was revealed, Allaah does not accept any other religion, because Islam annulated all religions that preceded it. Indeed, all other religions are full of unfounded beliefs and historical mistakes.
First, there is no authentic chain that confirms that these religions have authentic sources.
Second, even though the Bible is claimed to be the word of god, people made many versions of them because no original scripture was ever scribed and persevered since their revelation. This resulted in contradictions that can be noticed in the way the same event is described in the different copies.
Third, these sources, now, contain many false beliefs. The Jews - for instance, believe that Allaah made the earth and heaven in six days, got tired as a result. So, He had a rest the seventh day while the Christians believe that Jesus is the son of Allaah, exalted is Allaah far above such claims.
Fourth, these sources contain both words attributed to Allaah and those of people, and both are intermixed. Originally parts of those books have been from Allaah but much has been added to them by knowledgeable and unknowledgeable people of those religions. The above is but a short account that may help to understand the issue.
Allaah knows best.