Agnostic people tend to believe that you can not prove that God does or does not exist. They are in a middle space between atheists and religious folk. They do not really believe in anything (this may be different depending on the person).
Agnosticism would not be a valid form of religion and this is why. Agnosticism is having the view that the existence of God is unknown and unknowable, therefore from this perspective, God can’t be believed in. However, religion is having some sort of belief or worship of superhuman controlling power, or in other words, a God. Therefore, how could Agnosticism be a VALID form of religion, when religion is having some sort of belief/worship of God? Agnosticism contradicts Religion.