Why Love is so hard to be defined?

Why Love is so hard to be defined?
Exactly, main source is the Love.
That's what everyone is up to find,
That is that goes from ground to Above.

The one who makes the active, lusty searches
Coordinates in chances with the one,
Who fell in dreams of something great and gorgeous -
They both do live under the same Sun.

And anyways, affinity of passion,
Or Higher Love - it's all about the deal
That means the most impressive world's action,
That has to be immediately revealed.