To attain eternal happiness one must suffer. He who has reached the state of self-sacrifice has true joy. Temporal joy will vanish.
Abdu'l-BaháTo oppose knowledge is ignorant, and he who detests knowledge and science is not a man, but rather an animal without intelligence. For knowledge is light, life, felicity, perfection, beauty and the means of approaching the Threshold of Unity. It is the honor and glory of the world of humanity, and the greatest bounty of God. Knowledge is identical with guidance, and ignorance is real error
Abdu'l-BaháEvery kind of knowledge, every science, is as a tree: if the fruit of it be the love of God, then is it a blessed tree, but if not, that tree is but dried-up wood, and shall only feed the fire
Abdu'l-BaháTruthfulness is the foundation of all virtues of the world of humanity. Without truthfulness, progress and success in all the worlds of God are impossible for a soul. When this holy attribute is established in man, all the divine qualities will also become realized.
Abdu'l-BaháWe ask God to endow human souls with justice so that they may be fair and may strive to provide for the comfort of all that each member of humanity may pass his life in the utmost comfort and welfare. Then this material world will become the very paradise of the Kingdom this elemental earth will be in a heavenly state and all the servants of God will live in the utmost joy happiness and gladness. We must all strive and concentrate all our thoughts in order that such happiness may accrue to the world of humanity.
Abdu'l-Bahá