The phrase "missionary efforts" refers to the activities or work done by individuals or groups who go to different places to share their religious beliefs or help others in need. Full definition
Each faith requires missionary efforts to convert followers of other faiths. (religion-online.org)
It is a novel based on historical events, telling the very disturbing story of missionary efforts in Japan and the grim life, torture and the inevitable apostatizing that occurred during that time. (nakedpastor.com)
One of the most jarring aspects of the genocide in Rwanda is the fact that due to the ostensible success of Christian missionary efforts in that country during the 20th century, it had become one of the most thoroughly Christianized countries in Africa. (religion-online.org)