O thou spiritual friend! This world is a prison for heavenly souls, and this earthly world is but a cage, and not a nest, unto the divine birds. A prisoner who is awake and conscious will certainly seek for freedom, and a mindful bird will certainly wish for deliverance from the cage. When the heart becometh free from attachment unto this world, it will crave for the world of the Kingdom and seek for eternal life.
[link to reference.bahai.org]