What do Baha'i believe about the soul?
According to Bahá'í teachings, human nature is fundamentally spiritual and the essential identity of each person is defined by an invisible, rational, and everlasting soul.
Although undetectable by physical instruments, the soul shows itself through the qualities of character that we associate with each person. The soul is the focal point for love and compassion, for faith and courage, and for other such "human" qualities that cannot be explained solely by thinking of a human being as an animal or as a sophisticated organic machine.
The soul animates the body and distinguishes human beings from the animals. It grows and develops only through the individual's relationship with God, as mediated by His Messengers. The relationship is fostered through prayer, knowledge of the scriptures revealed by these Teachers, love for God, moral self-discipline, and service to humanity. This process is what gives meaning to life.
Despite its emphasis on the soul, the Bahá'í Faith does not encourage a negative view of the body. On the contrary:
Since the body is the vehicle of the rational soul in this life on earth, it is important to maintain and care for it. Bahá'u'lláh strongly discouraged any form of asceticism or extreme self-denial. His emphasis was on healthy discipline. Therefore the Bahá'í writings contain a number of practical laws relating to the care of the human body: proper nutrition, regular bathing, and so forth. ("On Good and Evil" – Bahai.org)