An adept once told me about the most powerful Mantra in the world - Shivoham or शिवोहम. Literally translated in English it means ‘I am Shiva’.
If you wonder how a man can ever be Shiva. It’s because in every individual is present in a potential form; the Ever-Existent whom we call Shiva.
Shivatattva is the highest principle in Indian Philosophy. This Tattva is that which is beyond everything; it is attribute less, unborn and changeless. Everything exists in this Tattva and this Tattva exists in everything.