The peace being promised is not an agreement between two parties who might later quarrel. It is everlasting because it does not depend on circumstance. It is the stillness that remains when you stop resisting this moment and let it be as it is.
The sanctuary is set in the midst of the people, not in some distant place. This is the whole teaching. What you seek is not far away or in the future. The deep quiet you are looking for is already here, at the center of your own presence. Come home to that inner space, and you find you were always dwelling in it.