Do you read all the answers for your questions???
I just reproduce that answer:
Its just a philosophy to understand the nature of your 'SELF' with that of 'GOD". Its says that both are not separate and so there is no duality of the spirit advaita against duvaita but they are one and the Jeevattma human soul ultimately reaches the Paramathma, namely the GOD! the eternal and immotal spirit. In the right sense you can worship the GOD in any way you chose from simple POOJA to heavy TAPAS which is not practiced nowadays! For the POOJA you can have a IDOL or even just a PORTRAIT and assume the same as your preferred GOD and complete the way you want any rituals or course as prescribed by the VEDAS or UPANISHADS. You must get the mental satisfaction on this practice and at one juncture you would find enlightenment in SELF which is the real SPIRITUALITY that everyone including those MAHANS wants to attain in life.