Nearly all different cultures believe in non physical dimension of existence what is opposite to physical. In many instances they think that those two dimensions have subtle interaction in which is non physical superior to physical.
People have deep-rooted idea about existence of consciousness without body under names of angels, spirit, fairy, nymph etc. That idea is not religiously based. Many non religious people have intuitive idea about it. Some people start to have that idea after death of close friends or relatives, some after NDE etc.
Questions are:
Why so many people with different backgrounds, cultures, religious believe have that idea? Where is that idea come from?
How wise is dismiss that idea without been able to prove it impossible?
How we can be so sure that all this what we notice and call physical existence dosn't give appearance of only possible existence, and that is not part of something more complex?
We can be in illusion that discovering physical we discover the whole what it is and not a part. Therefore our knowledge can't be without contradiction.
Argument of people who categorically denial any existence except physical is that all what they can see, notice or discover is this physical existence. But, that is something what we can expect because we are amid physical existence . As man goes under the water all what he can see and notice is the water or all his experiences must be trough water; and that dosn't mean that space without water dosn't exist.
In physical existence we can't see consciousness without body or matter because we conclude that matter and consciousness is the same and that one without other can't exist. That is based only on appearance and not on essence because we still don't understand, not only matter, but more impotently consciousness.