Ok. Am not sure I have a context to best explain this but will give it a go. And if I fail to communicate then I apologise - not trying to be an ass, just am still learning (albeit slowly perhaps).
For me, at times, I have felt like a prisoner of depression - unhappy and seemingly stuck in 'darkness.' Then, through various ways, I have experienced the shackles of
depression being released - whereupon there is a palpable sense of feeling 'lighter,' that joy is now able to freely flow through and as me. This might not fit in with other people's beliefs, it might not fulfil their need for evidence, might even lead to them telling you that you cannot be experiencing what you are. But it is a obvious as obvious can be.
Now, perhaps it is possible to take this idea and 'generalise.' For example I might say that I felt like I have been a prisoner of my own fears. As I come to face them and allow them to be released I come to feel a sense of freedom that some might call Love. Again, there might e those that say that because no-one can pin it down in a laboratory, then it can't exist. Do I listen to them or come to trust what within quite palpably is?
In this way I can find the likes of the bible BUT it can quite easily come to an extra heavily fortified prison - thus perhaps denying its original purpose and twisting its message.
So, one might be able to theorise about freedom from a prison but the real, practical evidence only comes from walking out of the prison doors.