Our Two Worlds
We humans have two worlds: The inner world, and the outer world. These worlds constitute our lives. I think the ability to connect these worlds is the most important thing in a human's existance.
Connecting these worlds comes from our will, the power of actualize our inner world onto the outer one, changing the latter. That creation is action.
The inner world has perks, such as infinite resources, unbounded connectivity, unruled creation. Imagination is such a powerful tool, because it can connect ideas that didn't exist before.
The outer world also has perks, such as the sense of reality. Our bodies, emotions, feelings, perceptions. All these are the experiences we are here for. If you were out of the material world forever, you wouldn't be able to create anything.
And that is the connection: the creation. Action in every sense of the word, creates. When we act, we move an infinite amount of probabilities. Our consciousness and will separates us from any other animal.
Action is why we're here. The ability to create in the material world what we have inside is limited to our lifetimes.