Book excerpt: In U.S. Population Projections: 2005-2050, Pew Research Center reported that "The nation's population will rise to 438 million in 2050, from 296 million in 2005, and fully 82% of the growth during this period will be due to immigrants arriving from 2005 to 2050 and their descendants." This shows that it is essential to study and understand how our mission, especially in the context of the USA, called the nation of immigrants, will respond to this huge mobility of immigrant diaspora. So far, there has been emphasis on doing diaspora missiology; however, there is no practical implications and application in local church setting. Now mission is next door, which implies that the ministry of the local church should be emphasized for 21st contemporary mission. This book provides detailed frameworks and methods of diaspora missiology within local churches, called 'diaspora mission church.' According to the Bible, all human beings are theologically and spiritually diaspora, irrespective of ethnicity, because they were banished from the Garden of Eden, and scattered around the world in God's judgment. Now, they walk toward the encounter with Jesus Christ, preach the gospel as the seed of Kingdom, and finally move toward heaven.