Mongolia is not overly religious, conservative, or liberal. Mongolians have a reputable history of having an open-minded attitude towards all religions. Historical records reveal that there were 12 Buddhist temples, 2 Islamic mosques, and a Christian church in the ancient capital city of the Great Mongol Empire in the Karakorum.
If you plan to visit any temples or monasteries, there are some social etiquette tips to avoid offending the locals. Such as, if you walk around a stupa or prayer wheels always walk in a clockwise direction. long-sleeved clothing is appropriate. Remove any hats, sunglasses before entering any monasteries and temples. Photography is not allowed in most monasteries.
Be respectful and do your best to go with the flow in order to have a good time. Religion in Mongolia has been traditionally dominated by the schools of Mongolian Buddhism and by Mongolian shamanism. Historically, through the Mongol Empire, the Mongols were exposed to the influences of Christianity (Nestorianism and Catholicism) and Islam, although these religions never came to dominate. Gradually, during the socialist period of the Mongolian People's Republic (1924-1992) all religions were prohibited, but with the transition to the republic in the 1990s, there has been a general revival of faiths.
The latest survey was conducted that 53% of the Mongolians identify as Buddhists, 38.6% as not religious, 3% as Muslims (predominantly of Kazakh ethnicity), 2.9% as followers of the Mongol shamanic tradition, 2.2% as Christians, and 0.4% as followers of other religions. Other sources estimate that a significantly higher proportion of the population follows the Mongol ethnic religion (18.6%).