1 Peter 1:1-2 reads: Peter an apostle of Jesus Christ, To God's elect, strangers in the world, scattered throughout Pontus, Galatia, Cappadocia, Asia and Bithynia, who have been chosen according to the foreknowledge of God the Father, through the sanctifying work of the Spirit, for obedience to Jesus Christ and sprinkling by his blood: Grace and peace be yours in abundance. The words strangers, foreigners, sojourners are words that help us understand how Peter is describing the Christians of his day. Since a Christian's highest citizenship is in heaven, we are strangers here.
We sing the words this world is not our home I am just a passing through and that is true. Our citizenship is in heaven and that's where our eternal home is with God. The real difference between Christians and others is not in a country, language, or even in different customs. The difference comes down to being Christ-like (Romans 12:1-2). We live and work in the world, but we too are strangers. At times we don't speak the language of our culture because it is foreign to us. We do not value what others value because it is foreign to us. We do not value what others value because the world is not our home. We make future, eternal investments. While we are stranger's here, we live with the assurance, that by God's grace we have an eternal home.