What is the meaning of eternal bliss?
Bliss is happiness. Eternal means forever and ever without end.
First you have to clarify what you mean by happiness. But we are Satchitananda - sat meaning being/existance, chit meaning consciousness, and ananda meaning bliss. We are bliss and happiness...and so is God...so realize who you are or find God (which is pretty much the same thing in the end). ~ Eric Putkonen
People say ignorance is bliss because the meaning of ignorance is to not have knowledge of something. Imagine a life where you had no knowledge of war, pain, suffering, hatred, etc. It would be bliss because you wouldn't know what anything other than being content was. Knowledge can be very painful sometimes, that is why.
Eternal Bliss would be something an enlightened person would experience. For example, through Zen or Bhuddist meditation it is possible to reach higher levels of consciousness with many years of practice and guided instruction. A person who experiences eternal bliss by being completely aware of the world around them, the good as well as the bad, yet their perspective, as well as their state of mind would remain unaffected by external events. It is not…