Religion vs Theosophy
There appears to be no difference at all between the two terms religion and theosophy, but strictly speaking there is some difference between the two. Religion is basically a set of beliefs related to the very existence of life; theosophy on the contrary is the doctrine of religious philosophy.
Religion
Religion is basically a set of beliefs related to the very existence of life believed to be created by supernatural forces.
There is every reason for the interchangeability of the two words religion and faith. Most religions of the world are characterized by the presence of distinct behaviors, distinct beliefs, distinct procedures of prayers and scriptural texts.
Morality, ethics and customs have firm bases in religion. In fact it can be said that it is in religion the elements of morality, ethics and customs find their support. The adherence to religion paves the way for culture. It is thus understood that different cultures of the world are due to the fact that they are sprung forth from the different religions of the world.
Religion involves spiritual practice as well. This is the reason why religious leaders are laden with spiritual knowledge as well. Religion and spirituality are of course two different planes.
Theosophy
Theosophy on the contrary is the doctrine of religious philosophy. Theosophy involves mysticism too. Theosophy involves spirituality in a greater percentage than religion. In fact it can be categorically said that while religion is all about beliefs and faiths, theosophy is all about spirituality alone.
If the religious faiths are rendered strong by spiritual practices, then they would pave the way for what is called as theosophy. Thus the word theosophy can be defined as any system of speculation that bases the knowledge of nature or mere existence upon that of divine nature or the spiritual knowledge.
Between religion and theosophy, it is true that the latter is on a higher plane since the theosophists firmly believe that other disciplines such as religion, science, philosophy and arts take people closer to the Supreme Absolute if they are coupled with spiritual knowledge.