Globalization of migration creates opportunities for missions on our doorstep. In Hong Kong, the number of ethnic minorities increased by 37% over the past ten years. Further, more Chinese from mainland China immigrated to Hong Kong. While the world focuses on the development of AI, fewer people are concerned about the development of relations between locals and newcomers. Closely related to Social Intelligence, Cultural Intelligence (CQ) is widely discussed in multicultural workplaces and is adopted in training missionaries and expatriates. As the number of newcomers rises and the number of Church members drops in Hong Kong because of immigration and emigration, building the CQ of Christians would enhance harmonious relations and communication in cross-cultural/subcultural missions on our doorstep. In this paper, I will discuss the development of CQ and survey the different applications of CQ in church ministries. Finally, considering my nearly eight years of experience and weaknesses serving in East Africa, I will propose a program of building CQ for churches in Hong Kong to engage ethnic minorities and newcomers and facilitate cross-generational ministries.