I think we have to give religion its due. I think we have to respect those for whom religion is important, but equally respect those who can achieve good morality without religion.
Resistance is a powerful motivator precisely because it enables us to fulfill our longing to achieve our goals while letting us boldly recognize and name the obstacles to those achievements.
If you always have something in your life that you're trying to improve upon, then every day you have a reason to get out of bed, and you have a reason to achieve something and feel good.