Answer
A citizen is a person who legally belongs to a country and has the rights and protection of that country. Citizens adopt the culture and practices of the nation or kingdom to which they belong. Every human being is born into the kingdom of this world, in which Satan rules (2 Corinthians 4:4). Consequently, we grow up adopting the culture, practices, and values that he instigates (Genesis 3:1; 1 John 2:16).
Satan’s kingdom enslaves its citizens (Romans 6:16). With darkened hearts and minds, we blindly follow our leader into the very sins that pull us deeper into slavery. We remain captives in this kingdom of sin, headed for destruction, until Jesus frees us (Ephesians 2:1–4). Philippians 3:18–19 highlights the differences between those who desire fellowship with Jesus Christ and those who focus on earthly pursuits: “For, as I have often told you before and now tell you again even with tears, many live as enemies of the cross of Christ. Their destiny is destruction, their god is their stomach, and their glory is in their shame. Their mind is set on earthly things.” Those who do not know Christ live only for this world and the pleasure they can find for themselves. They are “citizens” of this world and live by its rules and value system.
When we are born again by faith in Jesus Christ (John 3:3), we are born into the Kingdom of Heaven (Matthew 3:2; 7:21; Romans 14:17). Speaking of those who have had that spiritual rebirth, Philippians 3:20 says, “Our citizenship is in heaven. And we eagerly await a Savior from there, the Lord Jesus Christ.” Jesus spent much of His earthly ministry explaining the Kingdom of Heaven (Matthew 4:17). He compared it to many things, including a wheat field in which weeds grew along with the wheat. The plants appeared identical at first, but were separated at the harvest. The truth is, often the citizens of heaven and those of this world appear identical, and no one but God knows the difference (Romans 8:19). Many people may appear to be citizens of heaven, when, in fact, no rebirth has ever taken place in their hearts (Matthew 7:21).
When God grants us citizenship in the Kingdom of Heaven, we become “new creatures” (2 Corinthians 5:17). He sends His Holy Spirit to indwell our spirits, and our bodies become His temple (1 Corinthians 3:16; 6:19–20). The Holy Spirit begins to transform our sinful, worldly desires into those that glorify God (Romans 12:1–2). His goal is to make us as much like Jesus as possible in this life (Romans 8:29). We are given the power and privilege of exiting the world’s flawed value system and living for eternity (1 John 2:15–17). To be adopted into the family of God means that we become citizens of an eternal kingdom where our Father is the King. Our focus turns toward eternal things and storing up treasure in heaven (Matthew 6:19–20). We consider ourselves ambassadors to this earth until our Father sends for us and we go home (Ephesians 2:18–19; 6:20).
We live for a short time in these physical bodies, anticipating the bright future in our real home. While here, we share Abraham’s experience, living “like a stranger in a foreign country. . . looking forward to the city with foundations, whose architect and builder is God” (Hebrews 11:9–10).