For foreign citizens to live and work in the United States of America on a permanent basis, they must have a government-issued permanent resident card. Informally, this has been known as a Green Card. Without it, a foreigner is here illegally and may be arrested, fined, and possibly sent back to their home country. With it, a foreigner is able to live as a productive member of society.
Christians are like foreigners in another country. Paul wrote, “Our citizenship is in heaven” (Philippians 3:20). In a very real way, believers in Christ have another homeland, which is not here on earth. Jesus said, “My kingdom is not of this world” (John 18:36). It should feel as if we should have a Green Card even to have the permission to live here.