Not to “vacillate” in one’s determination to embrace the truth of this Cause”

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. Let him that seeketh, attain it; and as to him that hath refused to seek it - verily, God is Self-Sufficient, above any need of His creatures. 

- Baha’u’llah  (‘Kitab-i-Aqdas’; The Compilation of Compilations, Vol.II, The Importance of Prayer, Meditation and Devotional Attitude)