The reason words fail us when talking about a spiritual experience is because the deepest spiritual experiences take place within the mind of the individual. Even if shared with others there is no assurance that what you saw and heard was the same as the person next to you. Imagine if you will that we shared a spiritual experience and inhabited a spiritual space together and it was replicable. In time I would point to something or draw your attention mentally to some concept or feeling or experience within this spiritual realm and together we would develop language to describe what we were seeing and feeling. Much as you can point at an object and tell a baby what that object is called. The fact that these things are Indescribable has to do with them being non replicable and taking place in the isolation of one's mind.

Now if we are to assume as you say that all reality is a result of the Creator attempting to achieve pleasure, we must ask why did the creator end up this way? Our brains use pleasure and pain to drive us toward things that are good for us evolutionarily and away from things that can harm us. Why would a perfect god with no need to be filled and no survival imperative be subject to the same physical sensations as humans?