Brahman is often referred to as bliss. Bliss is ananda or the supreme happiness. When the state of bliss is experienced, we feel the happiness of the highest order. This happiness can never be attained by any other source except realising the Brahman. Therefore it becomes imperative that bliss can be experienced only if we know the Brahman, as he alone can cause bliss. There is a difference between bliss and happiness. Happiness is a state that can be attained through sensory organs. But bliss can be attained only from the source within. When you buy a new home or car you are happy, being a proud owner. But for experiencing bliss there is no object, as we have already ruled out the Brahman as an object. Secondly, the happiness is realised by your ego. You as an individual feel the happiness of possessing a new car. You can be defined as your gross form that is perishable. When you think about your gross body, your thought is associated with your ego. You know very well that ego is the destroyer. But in the case of bliss, it is not experienced through senses, but through realization.
When we say that bliss cannot be experienced by senses, it means that Brahman also cannot be enjoyed through sense organs. Therefore, we are ruling out that Brahman can be realized through our senses. He is beyond senses. He is beyond the senses because he is not visible, all alone and without qualities and attributes. Only form, qualities and attributes can be realised through senses. Therefore we can conclude that bliss and the Brahman are one and the same. But one may argue that when Brahman is omnipresent, why then the bliss is not attained always? It is true that Brahman is omnipresent. How do you know he is omnipresent? Because scriptures say so you believe that he is omnipresent, without experiencing his omnipresence. Unless his omnipresence is realized, you cannot experience the bliss. Hence practice of meditation becomes a necessity. Ignorance is the cause for identifying our gross body as the Self. Self means the Supreme Self, the Brahman. Identifying our gross body as the self is mainly due to two reasons. One is our ego and another is the maya or illusion. These two have to go, to progress in spirituality. But why there is impediment in realizing the Brahman who is also known as God, because, He is devoid of any quality, he is formless, and he is just watching ever activity as a witness. Because of these, we are not able to realise Him that easily. That is why importance of knowledge is emphasized in knowing the Brahman.
The scriptures say that the ultimate knowledge is not merely knowing and realizing Brahman, but becoming one with the Brahman. In the stage of knowing the Brahman or realizing him, there exists duality. But in the case of becoming one with him there is no question of duality. Only this stage is called liberation which is the highest stage one could think of. This stage can be achieved only by frequently experiencing the bliss. Meditation is the only way to experience the bliss.