The peace within us is not the peace in the environment. This is the peace within our being. It is entirely a matter of consciousness. We know that there is peace within us by the inner consciousness.
This consciousness of peace enables us to know that we are in the spirit. If we do not have peace, this indicates that we are not in the spirit. If we have peace, if we sense peace within us, this tells us that we are in the spirit.
Death first causes us to lose consciousness, because a dead person does not have any kind of consciousness.
On the one hand, death causes us to lose our consciousness, to become numb. On the other hand, death also causes us to have the sense of death. The sense of death is the sense of uneasiness, discomfort, depression, oppression, darkness, and emptiness. When we sense these things within us, this indicates death is within us.