The soul is the only part of a person that is eternal. However, the body is the vehicle through which we experience this world, and for that reason it deserves care and attention.
The soul and body have a close connection; each affects the other in important ways. Physical health and cleanliness have a powerful impact upon the quality of our spiritual lives, and our spiritual health influences our physical well-being.
The Baha’i teachings enjoin complete abstinence from drugs and alcohol, except when prescribed by a competent physician, and encourage moderation in diet and regular exercise. Just as purity of heart and mind are conducive to happiness, so is physical cleanliness:
… in every aspect of life, purity and holiness, cleanliness and refinement, exalt the human condition and further the development of man’s inner reality. Even in the physical realm, cleanliness will conduce to spirituality, as the Holy Writings clearly state. And although bodily cleanliness is a physical thing, it hath, nevertheless, a powerful influence on the life of the spirit. It is even as a voice wondrously sweet, or a melody played: although sounds are but vibrations in the air which affect the ear’s auditory nerve, and these vibrations are but chance phenomena carried along through the air, even so, see how they move the heart. A wondrous melody is wings for the spirit, and maketh the soul to tremble for joy. The purport is that physical cleanliness doth also exert its effect upon the human soul. – Abdu’l-Baha, Selections from the Writings of Abdu’l-Baha, pp. 146-147.
Baha’is believe we should seek healing by both material and spiritual means:
There are two ways of healing sickness, material means and spiritual means. The first is by the treatment of physicians; the second consisteth in prayers offered by the spiritual ones to God and in turning to Him. Both means should be used and practiced.
… they are not contradictory. Therefore thou shouldst also accept physical remedies inasmuch as these too have come from the mercy and favor of God, Who hath revealed and made manifest medical science so that His servants may profit from this kind of treatment also. – Ibid., pp. 375-376.
In times of illness Baha’is seek out the advice and assistance of competent physicians. Physicians themselves are advised not only to rely on their medical knowledge, but also to ask God for assistance in healing patients.
The Baha’i writings state that the spiritual and emotional dimensions can exert a powerful influence on one’s health. Many today are aware of the positive health effects of good attitude, a sense of purpose, a general feeling of well-being, of loving others and feeling loved. In addition to these we are assured of the power of prayer and the Holy Spirit to bring about good results. Many of us know of cases that were deemed hopeless, yet the patients recovered, due apparently to such influences.
Of course, prayer does not necessarily guarantee the outcome we desire. This is dependent upon God’s will. Abdu’l-Baha explains that we often do not understand the reasons for this in the short term, but that they are made known to us eventually. In one instance he also reminded a believer about the proper use of physical health:
If the health and well-being of the body be expended in the path of the Kingdom, this is very acceptable and praiseworthy; and if it be expended to the benefit of the human world in general—even though it be to their material benefit—and be a means of doing good, that is also acceptable. But if the health and welfare of man be spent in sensual desires, in a life on the animal plane, and in devilish pursuits—then disease were better than such health; nay, death itself were preferable to such a life. If thou art desirous of health, wish thou health for serving the Kingdom. I hope that thou mayest attain perfect insight, inflexible resolution, complete health, and spiritual and physical strength in order that thou mayest drink from the fountain of eternal life and be assisted by the spirit of divine confirmation. – Abdu’l-Baha, quoted by J.E. Esselmont in Baha’u’llah and the New Era, pp. 114-115.