How Can We Believe in Something We Can’t See?

I don't believe what I don't see

Seeing is not the only way to comprehend the existence of an object
As a matter of fact, human eye is rather limited and there are many things that we are not able to see even with the help of an instrument like a microscope or a telescope.
For example even though we can’t see our mind and our soul, we are not in doubt of their existence. Although we don’t see, we are sure that we have feelings and abilities. We are certain of them.
Similarly, the evidences of the existence of the Creator, angels, hell and paradise are so much that no human being having a mind doubts their existence. As a letter indicates the existence of its writer, everything in the universe indicates and proves the existence of Allah (swt) and the hereafter.