Impossible to Measure

At some point humans will not be able to understand reality to any greater detail. Our understanding is based on our ability to sense the reality around us. Our senses being based on the interactions with that reality means we are using the reality to measure and understand reality. Thus we can not understand that which we can not measure beyond our natural interaction with that being measured and by simply measuring the reality it changes from what it was before it was being measured because we interacted with it to measure it. If we can not sense it (future and past experiences) because it change from what it was does it exist? How do we really know that it was? If it is a god then we can not understand it because it changed when we measured it and for the claims of such understanding I find difficult to accept.