Recently, I was asked the difference between soul and spirit and initially did not really know the answer. On exploring further however, I found that all spiritual traditions explore it in their own ways but convey the same meaning.
As far as Hinduism is concerned, soul is the core-self and is defined by Shankaracharya as chit ananda rupa shivoham shivoham. Thus soul is consciousness which is a continuum filled with bliss and is always pure. We are surrounded by five koshas while one is alive and one identifies oneself with these koshas by ignorance of our inner self. The five koshas that are part of all of us are
The first kosha is annamaya, the physical body that is first thing we identify ourselves with.
The second kosha is pranamaya, the kosha composed of prana, or life force. This prana is a part of cosmic life. Each and every creature, each and every thing in this world is a part of cosmic life.
The third kosha is manomaya, the kosha composed of the mind. Mind is consciousness. It is a field of energy by itself.
Vijnana means psyche. Vijnana is a Sanskrit word from the prefix vi and jnana meaning knowledge or awareness, inner perception or experience. Vijnanamaya kosha is related to a very unknown part of the universe and it is a link or sutra between the conscious mind, the individual mind and the universal mind.
The fifth kosha is anandamaya kosha. Ananda is when there is no happiness and no unhappiness. It means a state of eternal bliss.
While we are composed of these five sheaths or koshas, we are not that as soul is beyond the koshas. Thus, soul is a central core of our being, while spirit consists of soul with an ability to reconstruct the body and thus reenters a suitable body and is reborn.
In Christianity, there is usually no difference between soul and spirit. We can carry our soul to where ever we are going because the soul is always with us. We exist in our subconscious mind, which is the soul, while not in a body. Our Spirit represent our true self, the spark of light, the Living Force. Somehow we are trapped into this material world via this body and we use it according to our desire and by the direction of Supreme Spirit (God) we utilize this body until it comes to an end.
Islam uses the words rûh and the nafs – both of which can be loosely translated as “soul” or “spirit”. The word rûh comes with the meaning of the divine infusion by which life takes place. The word nafs is more general in meaning than the word rûh and it just means sprit. I have personally come across the term rûh often as it is in romantic urdu shayri and poetry to convey meeting of soul mates.
Other faiths have their own explanation just like each language uses different terms and metaphors.
The most important fact is we all need to realize we are more than just the body, whether we can soul or spirit. Nomenclature apart, all that we need to realize is that whether we call it soul or spirit, we all are part of the same higher power and consciousness, come from the same source and shall return to the same destination.