The wisdom of the appearance of the spirit in the body is this: the human spirit is a Divine Trust, and it must traverse all conditions, for its passage and movement through the conditions of existence will be the means of its acquiring perfections. So when a man travels and passes through different regions and numerous countries with system and method, it is certainly a means of his acquiring perfection, for he will see places, scenes and countries, from which he will discover the conditions and states of other nations. He will thus become acquainted with the geography of countries and their wonders and arts; he will familiarize himself with the habits, customs and usages of peoples; he will see the civilization and progress of the epoch; he will become aware of the policy of governments and the power and capacity of each country. It is the same when the human spirit passes through the conditions of existence: it will become the possessor of each degree and station. Even in the condition of the body it will surely acquire perfections. 

Besides this, it is necessary that the signs of the perfection of the spirit should be apparent in this world, so that the world of creation may bring forth endless results, and this body may receive life and manifest the divine bounties. So, for example, the rays of the sun must shine upon the earth, and the solar heat develop the earthly beings; if the rays and heat of the sun did not shine upon the earth, the earth would be uninhabited, without meaning; and its development would be retarded. In the same way, if the perfections of the spirit did not appear in this world, this world would be unenlightened and absolutely brutal. By the appearance of the spirit in the physical form, this world is enlightened. As the spirit of man is the cause of the life of the body, so the world is in the condition of the body, and man is in the condition of the spirit. If there were no man, the perfections of the spirit would not appear, and the light of the mind would not be resplendent in this world. This world would be like a body without a soul. 

This world is also in the condition of a fruit tree, and man is like the fruit; without fruit the tree would be useless. 

Moreover, these members, these elements, this composition, which are found in the organism of man, are an attraction and magnet for the spirit; it is certain that the spirit will appear in it. So a mirror which is clear will certainly attract the rays of the sun. It will become luminous, and wonderful images will appear in it - that is to say, when these existing elements are gathered together according to the natural order, and with perfect strength, they become a magnet for the spirit, and the spirit will become manifest in them with all its perfections. 

Under these conditions it cannot be said, "What is the necessity for the rays of the sun to descend upon the mirror?" - for the connection which exists between the reality of things, whether they be spiritual or material, requires that when the mirror is clear and faces the sun, the light of the sun must become apparent in it. In the same way, when the elements are arranged and combined in the most glorious system, organization and manner, the human spirit will appear and be manifest in them. This is the decree of the Powerful, the Wise.1 

You have asked why it was necessary for the soul that was from God to make this journey back to God? . . . 

Man must walk in many paths and be subjected to various processes in his evolution upward. Physically he is not born in full stature but passes through consecutive stages of fetus, infant, childhood, youth, maturity and old age. Suppose he had the power to remain young throughout his life. He then would not understand the meaning of old age and could not believe it existed. If he could not realize the condition of old age, he would not know that he was young. He would not know the difference between young and old without experiencing the old. Unless you have passed through the state of infancy, how would you know this was an infant beside you? If there were no wrong, how would you recognize the right? If it were not for sin, how would you appreciate virtue? If evil deeds were unknown, how could you commend good actions? If sickness did not exist, how would you understand health? Evil is nonexistent; it is the absence of good. Sickness is the loss of health; poverty, the lack of riches. When wealth disappears, you are poor; you look within the treasure box but find nothing there. Without knowledge there is ignorance; therefore, ignorance is simply the lack of knowledge. Death is the absence of life. Therefore, on the one hand, we have existence; on the other, nonexistence, negation or absence of existence. 

Briefly, the journey of the soul is necessary. The pathway of life is the road which leads to divine knowledge and attainment. Without training and guidance the soul could never progress beyond the conditions of its lower nature, which is ignorant and defective.2

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