Question

It takes a force to change what?

Answer 1

Somethings are predestination, others are fate. But most changes take the force of mankind working together in unity.

Answer 2

That's kind of just evading the question, though...

Answer 3

According to physics, force cause changes to one's acceleration, direction, shape, etc. Force changes everything.

Here's more about that.
http://en.wikipedia.org/wiki/Force
http://www.physicsclassroom.com/class/newtlaws/u2l2b.cfm

Even though this is a writing group, and this is a more philosophical question, the same can be applied: force changes everything and every change requires force.