Baha'ullah wrote over 100 volumes of Writings. All those Writings are 'Most Holy', the Book of Laws is part of all these writings, the required balance for Humanity in this age.
Baha'u'llah has said about the whole Message from Allah;
"THE world’s equilibrium hath been upset through the vibrating influence of this most great, this new World Order. Mankind’s ordered life hath been revolutionized through the agency of this unique, this wondrous System—the like of which mortal eyes have never witnessed.
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.
Say: This is the infallible Balance which the Hand of God is holding, in which all who are in the heavens and all who are on the earth are weighed, and their fate determined, if ye be of them that believe and recognize this truth. Say: Through it the poor have been enriched, the learned enlightened, and the seekers enabled to ascend unto the presence of God. Beware, lest ye make it a cause of dissension amongst you. Be ye as firmly settled as the immovable mountain in the Cause of your Lord, the Mighty, the Loving."
Regards Tony