Martins was born in Rio de Janeiro, Brazil, and became an American citizen in 2010. The Martins family joined the LDS Church in 1972. In February 1978, Marcus Martins became engaged to Mirian Abelin Barbosa, who had just returned from serving in the church's BrazilSão Paulo South Mission. Initially they planned on getting married in May 1978, but then planned to postpone the marriage until after the dedication of the São Paulo Brazil Temple so Mirian could be sealed to her parents at the same time. However, she then decided to not follow that plan and they set a new marriage date of August 5. On June 8, 1978, Official Declaration—2 was announced. After much contemplation and prayer, Martins decided to serve a mission rather than get married. He served in the Brazil São Paulo North Mission from 1978 to 1980. After returning from his mission, Martins married Mirian. He worked as a construction inspector and later as a systems analyst. During this time he also served as a bishop in the church. In the early 1980s Martins was involved in making a new translation of the Book of Mormon into Portuguese. Martins then went to Provo, Utah, where he studied for six years at Brigham Young University, earning degrees in business management, organizational behavior, and a Ph.D. in Sociology. During his doctoral work he was a part-time Religion and Sociology instructor at BYU, and later worked as a religion professor at Ricks College, before taking a position at BYU-Hawaii in the Summer of 2000. As department chair at BYU-Hawaii he put forth initiatives to enhance religious education through the use of educational technology and public relations. He also served as chair of the Faculty Advisory Council, and member of the strategic planning and academic planning committees. He was the first BYU-Hawaii professor to work closely with BYU Television in taking academic lectures to an international audience. He has spoken to Latter-day Saint and professional audiences throughout the United States, Brazil, and Japan, and participated in professional conferences in China, Hong Kong, Malaysia, Singapore, the U.K. and Qatar. He has also used online tools to speak in live events in other nations. From 2011 to 2014, Martins served as president of the Brazil São Paulo North Mission. His upcoming second book is tentatively titled "The Priesthood: Earthly Symbols and Heavenly Realities."
