North Africa
According to Global Christian Relief, Islam is the fastest growing religion in the world. North Africa is primarily Muslim occupied and when in the country you can hear the prayer bells indicating a call to prayer. Here, Christianity is illegal and penalties can be stiff, including being deported or even martyred.
This makes living life as a Christian missionary not only difficult, but dangerous. Evangelism must be done through demonstration and not necessarily through words, sermons, or even churches. The non-existence of churches equates to a lack of discipleship, spiritual or community support.
It takes a special person/family to be called to these communities. Imagine raising small children in this environment where you want to teach them the word of God, but also have to be careful what is spoken in public. Missionaries, or workers, must learn the language, culture, and customs all without a local church. Families are few and burnout can be quick.