The Serenity Prayer is used as a mantra by Christians and non-Christians alike to redirect one's attention from the uncontrollable negative aspects of a situation onto the positive aspects that are controllable. It is also used in Alcoholics Anonymous and similar recovery organizations to emphasise willpower and self-control.
The Serenity Prayer has many different versions and iterations, but all of them focus on three main points as a means to teaching the person reciting the prayer to focus on control rather than worrying about the unknown. The first involves asking God or some higher power for the serenity to accept what one cannot change. In this case, serenity often means the inner calmness that comes with confidence in one's own abilities, rather than complacency. By accepting that some things are uncontrollable, one lets go of anxiety associated with trying to control every situation.
The second section focuses on the fact that everyone is capable of changing something in her life. In conjunction with the first section, this line shifts the attention from the negative to the positive. It helps to empower the person reciting it, reminding her that she does have control and strength and is not a victim to life. The final asks for the ability to distinguish between what one is and isn't able to change, which reminds the person that it is all an ongoing process.