As human started looking beyond the usual, several theories came into existence. Every new theory throws new light on what is going around us unseen, untouched, things that we can imagine but not feel. Like the string theory of vibrations. As per the string theory everything in this world is made up of tiny vibrating strings. It also says that these strings are identical. The theory explains how subatomic particles can feature both the properties of a particle as well as a wave.
M- Theory says that there are multiple universe and multiple dimensions right here and yet we cannot see them or touch them. Those dimensions could be right in front of us full of life moving together through this plain of existence and yet we can neither see them or touch them or feel them. It is said that normal matter account for less than 5% of the universe whilst 25 % is dark matter and 70% dark energy and we cannot see or feel either of them. Different school of thoughts, religion says God is omnipresent, omnipotent, he is present everywhere, around you. It seems to resemble the other theories in the fact that things can only be perceived and not touched and felt. These theories for normal humans seem strange and daunting. That brings us to the existence of God. Strange though it is hard to believe in these theories that speak of things we cannot see but they claim these exist. Likewise we speak about God and yet we cannot touch or feel his existence.