From Bahá’u’lláh
…it is indeed within the power of Him Who changeth the earth into another earth to transform all that dwell and move thereon. Wherefore marvel not at how He turneth darkness into light, light into darkness, ignorance into knowledge, error into guidance, death into life, and life into death. It is in this station that the law of transformation taketh effect. Ponder thereon, if thou be of them that tread this path, that all thou didst ask of this lowly One may be made plain unto thee and that thou mayest abide within the tabernacle of this guidance. For He doeth whatsoever He willeth and ordaineth whatsoever He pleaseth. Nor shall He be asked of His doings, whilst all men will be asked of their every deed. [cf. Qur’án 21:23] (Baha’u’llah, ‘Gems of Divine Mysteries’)
Immerse yourselves in the ocean of My words, that ye may unravel its secrets, and discover all the pearls of wisdom that lie hid in its depths. Take heed that ye do not vacillate in your determination to embrace the truth of this Cause--a Cause through which the potentialities of the might of God have been revealed, and His sovereignty established. With faces beaming with joy, hasten ye unto Him. This is the changeless Faith of God, eternal in the past, eternal in the future. (Baha’u’llah, 'The Kitab-i-Aqdas’; The Compilation of Compilations, vol. II, The Importance of Prayer, Meditation and Devotional Attitude)

