The Word of God Causes the Believer to Fulfill the Divine Covenant and the Unbeliever to Turn Away

In His Writings, the Bab explains that the same verses of His Book the Bayan attract the believer and veil those who reject Him:

"...on that Day whatever cause prompteth the believer to believe in Him, the same will also be available to the unbeliever. But when the latter suffereth himself to be wrapt in veils, the same cause shutteth him out as by a veil. Thus, as is clearly evident today, those who have set their faces toward God, the True One, have believed in Him because of the Bayan, while such as are veiled have been deprived because of it."
(Selections from the Writings of the Bab, p. 103)

Likewise, in the Book of Certitude Baha'u'llah states that His verses kindle love in the hearts of the faithful and that these same verses cause others to turn away:

"...compared with all other proofs and tokens, the divinely-revealed verses shine as the sun, whilst all others are as stars. To the peoples of the world they are the abiding testimony, the incontrovertible proof, the shining light of the ideal King. Their excellence is unrivalled, their virtue nothing can surpass. They are the treasury of the divine pearls and the depository of the divine mysteries...Through them floweth the river of divine knowledge, and gloweth the fire of His ancient and consummate wisdom. This is the fire which, in one and the same moment, kindleth the flame of love in the breasts of the faithful, and induceth the chill of heedlessness in the heart of the enemy."
(Baha'u'llah, The Book of Certitude, pp. 204-205, paragraph 226)

Likewise, Baha'u'llah quotes the first Arabic Hidden Word and states that it guides some and causes others to go astray:

“We shall impart unto thee a single word which We have taken from the essence of the Sacred Books and Scriptures as a token of Our mercy and loving-kindness, that the water of immortality may rain from the clouds of God's unity upon thy reality and the realities of His servants, and that thou mayest attain unto eternal and everlasting life. That word is this: 'Possess a pure, kindly and radiant heart, that thine may be a sovereignty ancient, imperishable and everlasting.' This is a treasure that pertaineth to Heaven. Were it to be quickened and to rise, it would never die or perish. This is a light that shall never be extinguished, a treasure that perisheth not, a raiment that shall never be outworn, and a revelation that will never be concealed. Through it many will go astray and others will be guided. Render thanks unto God that thou hast become the recipient of this All-Encompassing Word, this celestial melody and heavenly song. Had I found a word more conclusive, I would have divulged it. There is no greater counsel than this word. Preserve it if thou desirest to find a path to the Lord of the Mighty Throne.” (Baha'u'llah, "Book of the River," Provisional Translation by Nader Saiedi, "The Journal of Baha'i Studies" published by the NSA of Canada, Volume 9, #3, September 1999, pp. 60-61)

Similarly, Abdu'l-Baha wrote that the same divine tests cause some souls to progress, others to fall:

"O thou dear maid-servant of God! The souls who bear the tests of God become the manifestations of great bounties; for the divine trials cause some souls to become entirely lifeless, while they cause the holy souls to ascend to the highest degree of love and solidity. They cause progress and they also cause retrogression."
(Tablets of Abdu'l-Baha Abbas, Vol. II, p. 324)

This is a sentiment echoed by Marzieh Gail when writing of an important early believer who became estranged from the friends: "The same test which drives one soul away only confirms another." ("Arches of the Years," p. 99)

The same process occurs when the documents of the Covenant are promulgated. When Baha'u'llah's Will and Testament was read aloud, the faces of the faithful were joyful and the faces of the violators -- including the face of the Arch-breaker of Baha'u'llah's Covenant, Mirza Muhammad-Ali -- were saddened:

"The Kitáb-i-'Ahd was read ... on the ninth day after the ascension of Bahá'u'lláh in the presence of nine witnesses chosen from among Bahá'u'lláh's companions and members of Bahá'u'lláh's family, including Mirza Muhammad-'Ali. On the afternoon of the same day it was read by Majdu'd-Din in the Shrine of Bahá'u'lláh before a large company of the friends, consisting of the Aghsan, the Afnan, the pilgrims and resident believers. 'Abdu'l-Bahá says that after the Kitáb-i-'Ahd was read and its contents noted, some rejoiced with exceeding gladness and some grieved with great sorrow. The faces of the faithful were illumined with the light of joy, and those of the falsehearted were covered in the dust of despondency and gloom. 'Abdu'l-Bahá states that on that day the foundations of Covenant-breaking were laid ..."
(Adib Taherzadeh, The Covenant of Baha'u'llah, p. 150)

According to a letter I have seen written by Nellie French, a devoted American believer, the identical thing occurred when the contents of Abdu'l-Baha's Will and Testament were made known. When she received a letter with the good news, she rejoiced to learn that Shoghi Effendi had been appointed the Center of the Cause.  She went to the place of business of Mirza Ahmad Sohrab. She conveyed the wonderful news, expecting Sohrab to rejoice as she had. Instead he became very angry and said "This cannot be!" and repeated over and over that he, not Shoghi Effendi, should have been appointed. Thus was born a Covenant-breaker.

The same divine verses reassure the hearts of the faithful and cause the enemy to rebel.