What do Muslims believe? What is their belief system like?

The acceptance of the Qur'an as the main source and a guide is the cornerstone of the Islamic faith. Additionally, the most reliable historical sources for understanding Islam are the words and life of Prophet Muhammad (peace be upon him).

However, throughout history, various groups and sources of discord who aimed to distort religions have attempted to make additions or alterations to these sacred texts. They have fabricated lies for this purpose and commissioned the creation of various books by false religious scholars. Moreover, certain intelligence agencies have infiltrated target societies, pretending to be devout individuals, and caused the spread of false doctrines. Today, similar efforts can still be observed, and there are many memoirs and books related to this topic. By studying these sources, you can learn in detail how these spies infiltrated religions, how they behaved, and how they tried to propagate their own ideas .

I will continue to proceed with fundamental sources without boring you. I would like to talk about the most important source, the Holy Qur'an. This sacred book was revealed to Prophet Muhammad (peace be upon him) by the Angel Gabriel 1400 years ago.

Prophet Muhammad (peace be upon him) was descended from the lineage of Prophet Abraham. He grew up as an orphan, raised by his grandfather and uncles. His profession was shepherding, and he did not possess literacy skills. One of his most important attributes was the title "Al-Amin," meaning trustworthy, given to him by the people. This meant that even those who did not believe in him trusted him enough to entrust him with their valuables. There was a time when they even entrusted their weapons to him for safekeeping, even though they were planning an assassination attempt against him. The trust in his words was so deep that even wealthy and influential individuals would dismiss what he said about religion by saying, 'Someone has bewitched you,' because these words were spoken when his teachings contradicted their interests, knowing that he would not lie.  

Mecca and the Kaaba were places where people displayed their idols and profited from those who came for pilgrimage. It was essentially a trade for them more then a religion. However, the true religion sent by Allah  , which Prophet Muhammad (peace be upon him) propagated, rejected all idols, posing a significant threat to the rich people of Mecca. Moreover, the Jews knew that the last prophet would come in the Arabian Peninsula, but when they learned that the prophets didn't necessarily come from their own lineage and that the last Prophet Muhammad (peace be upon him) was an Arab, due to their arrogance, they attempted to kill him. Although the last prophet, Ibrahim (peace be upon him), was from the lineage of his son Ismail, and the Jews were from the lineage of Isaac, even though they were cousins, their arrogance prevailed.  

I won't go into detail about Prophet Muhammad because volumes of books can be written about him.

The revelation of the Qur'an to Prophet Muhammad (peace be upon him) began when he was 40 years old. The verses of the Qur'an were written by 42 scribes, the most famous of whom were Abdullah bin Sa'd in Mecca and Ubey ibn Kab in Medina. The Qur'anic verses were written on various materials such as paper, cloth, pieces of leather, stone, brick, and bone. During each Ramadan, the passages of revelation (the Qur'an) were presented from start to finish by Gabriel (peace be upon him) to Prophet Muhammad (peace be upon him), indicating where the new verses should be placed. Since revelation continued during the lifetime of Prophet Muhammad (peace be upon him), the Qur'an could not be compiled into a single book as new verses were continuously revealed. However, the text was memorized by many hafizs (individuals who memorize the Qur'an), and it was frequently recited within the community. Additionally, the presence of a trustworthy authority like Prophet Muhammad (peace be upon him) ensured the preservation of the text. Most importantly, approximately 3000 of his companions had memorized the Qur'an in its entirety.

After the passing of Prophet Muhammad (peace be upon him), the compilation of the Qur'an into a book was undertaken by the efforts of the Caliphs, including Abu Bakr, Uthman, and Ali. The oldest discovered copy of the Qur'an, dating back 1370 years, was found in Birmingham, England. This Qur'an matches the current text of the Qur'an letter for letter. Dr. Muhammad Isa Waley from the British Library expressed that this discovery was a source of great joy for Muslims. Additionally, Prof. David Thomas suggested that the person who wrote this Qur'an may have lived in that era, witnessed Prophet Muhammad, and had knowledge of his sayings. Another ancient copy of the Qur'an, dating from 1365 years ago, is made of gazelle skin and belongs to Caliph Uthman. There are hundreds of ancient copies of the Quran as examples, which are identical word for word to today's Quran.  

During the process of compiling the Qur'an, all the hafizs (those who had memorized the Qur'an) and written texts were collected, and the information in their memories was cross-verified to ensure the utmost accuracy without a hint of doubt before the text was recorded in the book. Reliable many individuals contributed to this process, and as a result, the Qur'an was compiled into a single book. During the time of Caliph Uthman, copies of this book were made and distributed. Allah has stated in the Qur'an itself that He has revealed it and will protect it.

The Qur'an, the book of Islam, is identical in every corner of the world. This is one of the most challenging aspects for those who seek to alter or corrupt it. Therefore, instead of trying to change the book of Islam, some have attempted to manipulate the words of Prophet Muhammad (peace be upon him). They have tried to create divisions among Muslims and cause harm by highlighting minor differences. Such efforts continue to this day. 

Hadiths are texts that contain the sayings and explanations of Prophet Muhammad (peace be upon him). They serve as an important source for elaborating on the Qur'an and providing guidance on how to implement its teachings in daily life. However, our primary source has always been the Qur'an. Hadith sources were formed as people began to record and collect the sayings of Prophet Muhammad (peace be upon him) shortly after his passing. Although some books were written during that period, the collection and recording of hadiths began during the time of the second Islamic caliph, Umar ibn Al-Khattab. These hadiths were sent to various Islamic territories. In a time when many historical sources are biased or misleading, hadiths can be considered the most reliable historical source because they were collected and written down immediately after the Prophet's death. Even if a hadith was heard from only one person, it would be mentioned along with details about the source. The age, mental state, and reliability of the narrator were scrutinized. If the narrator was deemed unreliable, the hadith was not accepted. There are also sources stemming from malicious interventions aimed at distorting and altering religion over time, but these sources are not accepted by Muslims who adhere to the preserved sources.  

In conclusion, we have the Quran, which has been proven to remain unchanged, and reliable sources like the Hadith books by scholars such as Bukhari and Muslim. These sources were written within the first 300 years of Islam. Those who wrote these valuable books conducted thorough research. Most importantly, we have a great guide, the Quran, which is protected by Allah , to evaluate the reliability of the Hadiths.

Finally, the beautiful character and life of Prophet Muhammad (peace be upon him), who was sent to us as a living example, is a valuable guide for Muslims. His life, filled with justice, mercy, patience, love for humanity, and tolerance, serves as a great source of inspiration. The life of Prophet Muhammad (peace be upon him) not only serves as a religious source but also as a moral guide, teaching us how to practice the beautiful moral values in our daily lives. The biography of Prophet Muhammad, known as Siyer-i Nebi, is  valuable as a moral guide for Muslims because the life of Prophet Muhammad (peace be upon him) teaches how to put into practice the beautiful moral values.