Philippians 3:20 NIV
But our citizenship is in heaven. And we eagerly await a Savior from there, the Lord Jesus Christ.
Heaven is not a promise to us, we are born as citizens when you are born again, you become a citizen of heaven, that’s why you had rights of son-ship, rights of citizenship, our citizenship is in heaven.
Ephesians 2:6 NIV
And God raised us up with Christ and seated us with Him in the heavenly realms in Christ Jesus,
Romans 8:14 NIV
For those who are led by the Spirit of God are the children of God.
When you are born again, you have a witness in your self that you are a child of God, if you don’t have that witness there are chances that you are not born again.