What is so exclusive to be part of a family? Your right to be part of a family comes from being born into that family. The same way is it with God's family. If we want to be part of the family of God, we have to be born into it, not through the flesh, but through the His Spirit. 
To be born of the Spirit or born again, means that we have to confess the name of Jesus Christ, believe in the work that He has don on the cross for us and be willing to submit our lives to His Lordship.

This invitation is open to everyone.
There is no "exclusiveness". We deside if we want to be in our out.