When the soul leaves the body…

When the human soul soareth out of this transient heap of dust and riseth into the world of God, then veils will fall away, and verities will come to light, and all things unknown before will be made clear, and hidden truths be understood

- ‘Abdu'l-Baha  (Selections from the Writings of 'Abdu'l-Baha)

The body draws its sustenance from the soul

The soul of man is the sun by which his body is illumined, and from which it draweth its sustenance… 

- Baha'u'llah  (‘Gleanings from the Writings of Baha'u'llah’)

The “soul retains its individuality and consciousness after death”

...The possibility of securing union with his beloved in the next world is one which the Bahá'í Teachings are quite clear about. According to Bahá'u'lláh the soul retains its individuality and consciousness after death, and is able to commune with other souls. This communion, however, is purely spiritual in character, and is conditioned upon the disinterested and selfless love of the individuals for each other. 

- Shoghi Effendi (From a letter written on behalf of Shoghi Effendi to the National Spiritual Assembly of India, March 10, 1936: ‘Dawn of a New Day’; compilation: ‘Lights of Guidance’)

The station of a believer’s non-Baha’i parents in the next world

Thou hast mentioned the station of parents in the next world. One of the special bounties of this Revelation is that whoever accepteth the Dayspring of the Cause, his parents, although they may not have attained the recognition of the Revelation, the splendours of the Sun of divine favor will be vouchsafed unto them. This is one of His bounties bestowed upon His lovers. Render thanks and be of those who are grateful. 

- Baha’u’llah  (Quoted in a Memorandum from the Research Department of the Universal House of Justice, dated 28 August 1991)

The condition of non-Baha’i relatives after death -- explanation by the Research Department of the Universal House of Justice

The Research Department has studied the questions about the spiritual condition of souls of the non-Baha'i relatives of Baha'is, which were contained in the letter dated 26 July 1991 from Mr…. to the Universal House of Justice. Mr…. cites the following extract from a Tablet revealed by Baha'u'llah and raises a number of issues about its meaning and application:

These blessed words were uttered by the Tongue of Grandeur in the Land of Mystery, [Adrianople] exalted and glorified is His utterance: 

One of the distinguishing characteristics of this most great Dispensation is that the kin of such as have recognized and embraced the truth of this Revelation and have, in the glory of His name, the Sovereign Lord, quaffed the choice, sealed wine from the chalice of the love of the one true God, will, upon their death, if they are outwardly non-believers, be graciously invested with divine forgiveness and partake of the ocean of His mercy.

This bounty, however, will be vouchsafed only to such souls as have inflicted no harm upon Him Who is the Sovereign Truth nor upon His loved ones. Thus hath it been ordained by Him Who is the Lord of the Throne on High and the Ruler of this world and the world to come. (Baha’u’llah, The Compilation of Compilations, vol. 1, Family)

“…soul is as the sun, and... mental faculties even as the rays that emanate from that source of light.”

…regarding the question whether the faculties of the mind and the human soul are one and the same. These faculties are but the inherent properties of the soul, such as the power of imagination, of thought, of understanding; powers that are the essential requisites of the reality of man, even as the solar ray is the inherent property of the sun. The temple of man is like unto a mirror, his soul is as the sun, and his mental faculties even as the rays that emanate from that source of light. The ray may cease to fall upon the mirror, but it can in no wise be dissociated from the sun. 

(‘Abdu’l-Baha, ’Tablet to August Forel’)

The “spiritual world” and the “phenomenal world” are the “exact counterpart of each other”

The spiritual world is like unto the phenomenal world. They are the exact counterpart of each other. Whatever objects appear in this world of existence are the outer pictures of the world of heaven.

(‘Abdu’l-Baha, from a talk, 13 April 1912, New York; ‘The Promulgation of Universal Peace’)

Human “soul is endowed with two wings”

Know also that the soul is endowed with two wings: should it soar in the atmosphere of love and contentment, then it will be related to the All-Merciful. And should it fly in the atmosphere of self and desire, then it will pertain to the Evil One; may God shield and protect us and protect you therefrom, O ye who perceive! Should the soul become ignited with the fire of the love of God, it is called benevolent and pleasing unto God, but should it be consumed with the fire of passion, it is known as the concupiscent soul. Thus have We expounded this subject for thee that thou mayest obtain a clear understanding. 
(Baha'u'llah, Súriy-i-Ra’ís, ‘The Summons of the Lord of Hosts’)