Islam like Buddhism and Christianity is a proselytizing religion, which has quickly expanded its religious boundaries since its beginning from the Arabian Peninsula in the 7th century to the rest of the world. By expanding to Africa, Europe, and Asia via the work of imams and merchants Islam became a world religion in a short time. Islam reached Korea at the end of the 9th century during the Shilla Dynasty, but its religious influence was insignificant back then. STATISTICS KOREA (2015) reported that Christianity and Buddhism have become two largest religious groups, each having 13,566,000 and 7,619,000 members respectively. Among Christians, Protestants (9,676,000) are about 2.5 times more numerous than Catholics (389,000). STATISTICS KOREA (2015) did not include Islam in its survey, but estimated that there are about 100,000 Muslims in Korea. Albeit small in number, Muslim population in South Korea has been steadily growing since 1950s, and numerous Koreans converted to Islam even after a flood of negative media coverage about Islam through the formation of the Islamic State of Iraq and the Levant (ISIL, ISIS or Daesh) in 2014. I am concerned about Islam and its explosive growth of Muslim population in the 21st century around the world and particularly in South Korea. This paper suggests missiological approaches and reasons to better understand the Muslim community in Korea before sharing the message of the kingdom of God.