Of the most central elements of religions and most important issues in theology and the Contemporary study of religion is the category of faith and its greatest impact on various aspects of life. Faith, in Islamic and Christian theology, has common and also distinct aspects. The truth of Faith in Islamic thought was multidimensional and consists of a wide range of Confession of language, intellectual knowledge, heart affirmation and inner experience to the treatment involves external actions. In Christianity, it was faith in confirmation of the revealed proposition that led to a sense of transcendence and meta-proposition and created Interest mode in human And sometimes faith apply to the experience of presence and manifestation of God in life.   The position of consensus and association between Islam and Christianity was consists of the doctrine of Belief in God and the prophecy and resurrection. This belief is based on the functionalist view affected on body and psyche (or soul) health of the human. The impact of Faith on physical and mental health has been separately approved by the specialists. The impacts of faith and religious teachings on physical health have been investigated through psycho-neuro-physiological way that Faith and Religious teachings produce positive emotions in human. The emotions through autonomous nervous system strengthen the immune system and its optimal performance in a way that the messenger molecule called neuropeptide Y, carry the messages related to thoughts and transport it through the blood circulation, and the mental state directly relate to the body's cells. This is the most important factor in strengthening or weakening the immune system influenced by the thoughts and beliefs. Moreover, Te'osumatic medicine known as the God-body medicine, after the psychosomatic or psycho-body medicine confirms the impact of faith on the health and recovery of individuals. They believe that illness and death of individuals, scarcely have a single cause, mind and mental and psychic states of the individual affects the incidence process of the disease and treatment Although they does not reject the effect of bacteria and viruses and etc. These medical professionals have presented seven principles for recovery and treatment of diseases, in particular, the incurable disease such as cancer that the first principle is belief in God (faith). but the effect of faith in mental and psychic health has been approved in other forms. Faith in the field of psychology equal with religious attitude and orientation. According to a number of studies, researchers have confirmed that there is a positive relationship between the religious attitude and mental health. The author's analysis the religious faith and religious attitudes and belief that there is a minimal relationship between religious faith and religious attitudes, so there is a relationship between faith and mental health.    According to what passed, the common faith, in the view of functionalism impacts on the health of body and spirit of man. This has been approved in the field of body health through psychoneorophysiologic and Te'osumatic medicine, and in the field of mental and psychic health has been approved by the researches have done in psychology titled "religious attitudes and orientation and mental health".