The Greers work with Mustard Seed Network to plant churches in unreached areas. In 2011, they planted their first church in Osaka, Japan, and in 2020, they planted a church in Tokyo, the core of the world’s largest urban area by both population (37 million people) and economy ($2 trillion). This church continues to grow and is part of a larger church-planting movement to reach Japan with the hope of Christ.