... the love of God is essential ...

That divine world is manifestly a world of lights; therefore, man has need of illumination here. That is a world of love; the love of God is essential. It is a world of perfections; virtues, or perfections, must be acquired. That world is vivified by the breaths of the Holy Spirit; in this world we must seek them. That is the Kingdom of everlasting life; it must be attained during this vanishing existence. By what means can man acquire these things? How shall he obtain these merciful gifts and powers?
 First, through the knowledge of God. Second, through the love of God. Third, through faith. Fourth, through philanthropic deeds. Fifth, through self-sacrifice. Sixth, through severance from this world. Seventh, through sanctity and holiness. Unless he acquires these forces and attains to these requirements, he will surely be deprived of the life that is eternal. But if he possesses the knowledge of God, becomes ignited through the fire of the love of God, witnesses the great and mighty signs of the Kingdom, becomes the cause of love among mankind and lives in the utmost state of sanctity and holiness, he shall surely attain to second birth, be baptized by the Holy Spirit and enjoy everlasting existence. 

`Abdu'l-BaháThe Promulgation of Universal Peace