Peace? Is it defined by the absence of war, danger, conflict or internal struggle?
Or is it just a blissful sense of self, beyond space, time, description or explanation? Can this exist in a hostile or dangerous environment, or is the person who stays calm under all circumstances just faking it?
How do you meditate when the neighbors are in a loud screaming match? Some teachers would advise sending them love without judgment, neutral acceptance of the sounds, no different than the wind or the noises of traffic. As you go deep into yourself and the brainwaves slow, you can create an imaginary bubble around yourself that is unaffected by light and sounds outside.
Is religion a path to peace? Many find that taming the mind with a structure of beliefs, acceptable behaviors and revered authorities can bypass or quiet inner fear and turmoil. Certainty that you have been given the absolute truth can be immensely comforting.
Atheism has its own structure of beliefs: the certainty here is the absolute truth of Science - nothing that cannot be measured is real. There can be great comfort and self-satisfaction in ridiculing those who espouse spirituality or anything beyond physical existence. In this world view, consciousness itself is seen as a side effect of physical and biological structures.
Eastern religions can provide very valuable tools to remove the mental barriers to real inner peace. There are many other practices that accomplish the same thing, some more effectively than others. The traps here occur when the seeker is taught dependence on a single organization, belief set, guru, leader or spiritual master as the only path to enlightenment.
Real peace of mind is more than just freedom from inner turmoil, in fact, it has NOTHING to DO with the mind. Realization of your true self is like a powerful awakening, that washes away thoughts, fears and anything else other than pure, loving awareness. It is a dynamic aliveness that gives meaning to the phrase "Peaceful Warrior".
Searching for this "true self" can look like sifting through dozens of masks, identities and self-images to figure out which one is the "real me". One by one they can be examined and discarded, because, in truth, you are not ANY of those. That which looks from behind your eyes is just AWARENESS! It cannot be described or defined by space, time, shape or color. It is simply YOU.
Intellectual understanding of this is just a pale shadow of the grand experience of AWAKENING to the pure SIMPLICITY of who you are. There are MANY tools and methods to steer you to this, but do not mistake the tools for the undefinable realization that they point to.
For those who have this awakening, the path has not ended. The realization continues to deepen, with increasing beauty and joy. The mind cannot grasp the peace that is found here, because it truly passes all understanding.