If we wish to deny everything that is not sensible, then we must deny the realities which unquestionably exist. For example, ethereal matter is not sensible, though it has an undoubted existence. The power of attraction is not sensible, though it certainly exists. From what do we affirm these existences? From their signs. Thus this light is the vibration of that ethereal matter, and from this vibration we infer the existence of ether.
Bahá'í World Faith, page 307
The fifth candle is the unity of nations - a unity which in this century will be securely established, causing all the peoples of the world to regard themselves as citizens of one common fatherland.
The Seven Candles of Unity
[The permanent peace] will be established in this century ... It will
be universal in the twentieth century. All nations will be forced
into it ... the nations will be forced to come to peace and to agree
to the abolition of war ... By international agreement they will lay
down their arms and the great era of peace will be ushered in."A Compilation on Peace" compiled by the Research Department of the UHJ
"all nations and kindreds will be gathered together under the shadow of this Divine Banner, which is no other than the Lordly Branch itself, and will become a single nation. Religious and sectarian antagonism, the hostility of races and peoples, and differences among nations, will be eliminated. All men will adhere to one religion, will have one common faith, will be blended into one race, and become a single people. All will dwell in one common fatherland, which is the planet itself."
This is the stage which the world is now approaching, the stage of world unity, which, as `Abdu'l-Bahá assures us, will, in this century, be securely established.
Shoghi Effendi, quoting "Some Answered Questions" in "The Promised Day Is Come"
... in this luminous century the greatest bestowal of the world of humanity is Universal Peace, ...
Star of the West, vol. VII, page 136; Peace Compilation
Now the glorious and brilliant twentieth century has dawned, and the divine bounty is radiating universally ... Truly, this can be called the miracle of centuries, ...
Promulgation of Universal Peace, page 153; Peace Compilation
Now in the world of being the Hand of divine power hath firmly laid the foundations of this all-highest bounty and this wondrous gift. Whatsoever is latent in the innermost of this holy cycle shall gradually appear and be made manifest, for now is but the beginning of its growth and the dayspring of the revelation of its signs. Ere the close of this century and of this age, it shall be made clear and evident how wondrous was that springtide and how heavenly was that gift!
World Order of Baha'u'llah, page 111
Thou hadst asked some questions; that why the blessed and spiritual souls who are firm and steadfast, shun the company of degenerate persons. This is because, that just as the bodily diseases, like consumption and cancer are contagious, likewise the spiritual diseases are also infectious. If a consumptive should associate with a thousand safe and healthy persons, the safety and health of these thousand persons would not affect the consumptive and would not cure him of his consumption. But when this consumptive associates with those thousand souls, in a short time the disease of consumption will infect a number of those healthy persons. This is a clear and self-evident question.
Likewise, if a thousand magnanimous persons associate with a degraded one, the perfection of those souls will not affect this debased person. On the contrary, this mean person will be the cause of their going astray. Therefore, His Holiness Bahá'u'lláh says in the Tablets: "Soon will a foul odour be spread; shun it, so commandeth the Omniscient and the Wise. That is, in that city a stinking odour will soon be spread. You should avoid it. So are ye commanded by His Holiness, the Knower and the Wise." That foul odour is that of violation. Also in the Tablet of Advice He says: "Now, do not neglect your Sower, Protector, and Educator; and do not choose and prefer others to Him, lest foul and poisonous winds should pass over you."
His Holiness Christ says that the owner of the garden does not leave the dried tree, but certainly cuts it and throws it into the fire, because the dried wood is worthy and deserving of fire.
Again, His Holiness Bahá'u'lláh says: "Then, O ye trees of the blessed garden of My bestowal, protect ye yourselves from the poison of the treacherous souls and the stinking winds, which are the association of the polytheists and the negligent ones, so that the trees of existence, through the bounty of the Worshipped [God] be not deprived of the blessed breaths and breezes of love."