First thing I've ever done

I am the diamond
I am the world
I am the one
I am the only
I am the rich
I am the poor
Be pinned to someone’s shirt, be seen by people and not be
Hurt
I’m just down the hill and in the house, up the stairs and to the left
I’m always in a church or in a box
In a house or on a human
Its just you and me for ever and ever