Focusing on the early Pahlavi period the article is aimed at showing the tendencies and processes of development of Christianity among the Iranians as well as the circumstances under which the Protestant believes were communicated, debated and assimilated by the Iranian converts. Adopting the historical methods for describing the social changes that occurred in Iran as a result of the authoritarian policy of the Iranian monarch Reza Shah the article reveals the concept of conversion as a change of values arguing that the converts constructing and imagining their identity remained Iranians by keeping the most valuable feature – the Persian language. Thus, the religious conversion was associated with the concept of Iran-ness (iraniyyat) yet an alternative to the state national policy at that time.