When Isaac Newton wrote about the Laws of Motion, he was thinking of forces that move our physical world. One law of motion he talked about was the principle of inertia. It's the tendency of an object to stay at rest or in motion unless an external force acts upon it. The use of a seat belt in a moving vehicle is a practical application of the principle of inertia.
Inertia also has another meaning in the human world. Sad to say, I'm currently a good example of being in an inert condition. I've been inactive from running for the past two months. I sit on the couch watching TV for hours, go to bed late, and eat late night snacks. They aren't really the hardest things in the world to do; but, who'd want to do something else?
There lies the problem with inertia. It's a disposition to stay unchanged.
Overcoming inertia in people's ways is not that simple. During this time when I was attached to the couch, I came to realize there is no amount of external force to overcome human inertia. The force has to come from within.
It's called willpower. It's that inner strength to take action in the face of difficulties and resist the temptation to take the easy way out. A strong willpower is deeply anchored in our faith in God. And we strengthen our willpower by striving to live a life of prayer. Praying daily, I am mustering my willpower to move me out of the couch and hit the road again.