do u believe in life after death?

Some had Near-death experiences.

They told of feelings of peace and joy, time speeded up, heightened senses, lost awareness of body, seeing a bright light, entering another world, encountering a mystical being and coming to "a point of no return".

Does it really exist or not? "To be or not to be, that is the question."
If it does exist, do we know that it exists? A thing can obviously exist without our knowing it.
If we know that it exists, can we be certain of this knowledge? Our knowledge might be true but uncertain; it might be "right opinion."
If it is certain, is there a logical proof, a demonstration of why we have a right to be certain? There may be some certainties that are not logically demonstrable (e.g. my own existence, or the law of non-contradiction).
If there is a proof, is it a scientific one in the modern sense of 'scientific'? Is it publicly verifiable by formal logic and/or empirical observation? There may be other valid kinds of proof besides proofs by the scientific method.