In chapter 36 of Some Answered Questions, Abdu’l-Baha identifies the spirit of heaven as the light rays that emanate from the Sun of revelation (that is, the Manifestation of God). It is the bounty of God. If a person chooses to focus their attention up toward the Sun of revelation, the mirror of their soul is illumined with the spirit of heaven. When this happens, the true purpose of the person’s existence becomes evident. All human beings are created to radiate the light of God and to display God’s attributes through themselves.
“Today you should consider all things to be mirrors. For all creation was brought into being by a single word, and is standing in one spot in the presence of God. If all would turn their attention to this glorious and eternal sun, which has dawned forth from the holy and most glorious horizon, the effulgence of the sun would be inscribed and imprinted on their forms. In this case, all the characteristics and attributes of the sun are also true of those mirrors, for nothing is apparent in those mirrors save the sun and its light.”Commentary on a Verse of Rumi, paragraph 7, trans Juan Cole
The process whereby a person is lit up by the spirit of heaven is the same thing as what is meant by the Christian concepts of rebirth and eternal life. The radiance of the spirit of heaven in the soul causes a person to wake up to, or be born into, the realm of Paradise. It is like a person waking up to the physical world in the morning after a night’s sleep. A person who is asleep has no awareness of the physical world and would sincerely deny its beauty and benefits. It is the same for a person who does not turn the mirror of the soul up to the Word of God. That person remains asleep to the heavenly worlds, and their wonders and benefits. Such a person might spend their entire life exploring the physical world and discover amazing things, but they will have ignored a huge part of creation.
The term eternal life can cause confusion because the human spirit, or soul, is a divine essence and cannot pass out of existence. In this sense, all human beings exist eternally. What is meant by eternal life is the new life a person wakes up to if they turn their face toward the Sun of revelation and allow the spirit of heaven to enter. Once a person wakes up to the heavenly realm, they can begin a new life in those heavenly worlds.
The fact that people can lead completely different lives in the spiritual realm is also apparent in the physical world. People can have heavenly lives or hellish lives during their time on earth too. Both of these experiences happen in the same physical world. For example, a person who lives in a nice home and does not want for anything lives a completely different life to someone who lives in dire want. In the same way, life in the spiritual worlds, after physical death, can vary infinitely. A person who turns toward the Sun of revelation and allows the grace of God to shine in their soul will find themselves in a glorious reality that others cannot know.
This distinction is apparent the following hidden word:
“O child of the cloud of mystery, I call you to immortality and you desire extinction. Why have you passed up what we want and settled for what you want?”Arabic hidden word 23, my translation
If the hidden word is read literally, it would mean that a person who turns to Baha’u’llah defies extinction and has won immortality; in other words, that person lives eternally in the spiritual world after death, while everyone else comes to an end in the grave. But that is not what Baha’u’llah means. He is using the word “immortality” to refer to life in the worlds of Paradise, and the word “extinction” to refer to life in the spiritual worlds without the presence of God. And in fact, Baha’u’llah explains that a person can attain “immortality” while still living in the physical world.