Turkey, like many other countries in the Middle East and North Africa, adopted Islam as its dominant religion in the 7th century CE. The spread of Islam in Turkey and other parts of the world was complex and varied. It involved a combination of military conquest, political and economic factors, and the missionary work of individual believers.

One of the critical factors that contributed to the spread of Islam in Turkey was the rapid expansion of the Islamic empire during the 7th and 8th centuries. The Arab armies of the new Islamic state conquered a large territory that included parts of present-day Turkey. 

As they conquered new lands, they also brought with them the teachings of Islam. Many people who lived in these conquered lands converted to Islam voluntarily or under duress. Over time, Islam became the dominant religion in these areas.

In addition to the expansion of the Islamic empire, the spread of Islam in Turkey was also facilitated by the appeal of the religion to many people who saw it as a more equitable and just system than the societies that preceded it. 

The teachings of Islam emphasized the equality of all believers and the importance of justice, and these principles may have resonated with many people in the region.

Over time, Islam became deeply rooted in Turkish society, and it continues to be the dominant religion in Turkey today. However, it is essential to note that there is diversity and variation within the Muslim community in Turkey, and not all Turkish Muslims necessarily hold the same beliefs or follow the same practices.