Happy is the man that hath apprehended the Purpose of God in whatever He hath revealed from the Heaven of His Will, that pervadeth all created things.

Bahá’u’lláh, Gleanings from the Writings of Bahá’u’lláh, p. 335

Happy is the man who hath recognized Thee, and discovered the sweetness of Thy fragrance, and set himself towards Thy kingdom, and tasted of the things that have been perfected therein by Thy grace and favor.

Bahá’u’lláh, Prayers and Meditations by Bahá’u’lláh, p. 54

Observe My commandments, for the love of My beauty. Happy is the lover that hath inhaled the divine fragrance of his Best-Beloved from these words, laden with the perfume of a grace which no tongue can describe.

Bahá’u’lláh, The Kitáb-i-Aqdas, p. 20

In the Bayán no act of worship is nearer unto His acceptance than bringing joy to the hearts of the believers, and none more remote than inflicting sorrow upon them.

The Báb, Persian Bayán VII, 18

Therefore, in the Bayán there is no act of obedience that ensureth greater nearness to God than bringing joy to the hearts of the faithful, even as naught yieldeth more remoteness than causing them grief. This law is doubly binding in dealing with the possessors of circles (women), whether in causing them joy or grief. However, man must always be watchful that even if he fail to bring joy to a human being, at least he should refrain from causing him grief.

The Báb, Persian Bayán 7, 18, quoted in Gate of the Heart: Understanding the Writings of the Báb by Nader Saiedi, p. 322

"Then it is impossible to attain happiness without suffering?"

‘Abdu’l-Bahá. -- "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-Bahá, Paris Talks, p. 178