When examining the kalām books within the classical period, what may be surprising to us at first glance is the great importance that has been given to language in their theological discussions and the recognition of linguists (ahl al-lugha) as an authority. Whenever Muslim Theologians (mutakallimūn) deal with any issue, they first determine how linguists would make sense of those relevant terms, and then explain it in a way that is appropriate for use in the Arabic language. This sensitivity of theologians in the language is not only limited to defining the terms of Islamic creeds, such as ‘faith’, ‘infidelity’, ‘revolt’ and ‘justice’, but also includes the definition of terms of physics and cosmology. In other words, while the mutakallimūn of the classical period conceptualize terms such as ‘universe’, ‘bodies’, ‘substance’, ‘accidents’, ‘motion’, and ‘rest’, they mostly take into account how the speakers of language use them. This article seeks to answer the question of why mutakallimūn regard the language as an important discipline, alongside cosmological issues, in the context of the relation between language, thought, and being. Perhaps by making a thought system based on Arabic language that happened to emerge in their regions as a result of long-time interactions with the natural environment and consequently became conveyers of particular worldview and way of thinking, they aimed to resist the impact of Greek worldview and logic that poured into the Islamic world from all ends via translations. In other words, the primary reason as to why the mutakallimūn considered language as an authority in theological and cosmological discussions was because they saw language, with its structure and concepts, as a carrier of their traditional worldviews and their way of thinking.