Peace is lies within one's self'.
According to '' Mansoor AL hallaj '' most of the people prefer body instead of soul that's why they are materialistic or con_substantial. I think is it as he says.Peace lies within satisfaction of soul rather then body, like if we steal some money so our body feel good i-e because our body need food and at that time body get lavish food and cloths but at the same time inside we feel regret it's mean we just making happy our body rather then soul.
Peace need satisfaction of mind and heart
if we do injustice our heart mourn and mind distract both are not agree with our deeds, we just trying to satisfy our mind and heart that's we didn't done any thing wrong,all people doing same if we did so what's wrong in it. It's mean the heart and mind have sort of connection with soul.
Which part will suffer body or soul..
When we died Almighty Allah take our soul and left the body in the grave, because the body is happy in worldliness body have no offense if we tell lie, snatch, steal, do bad deeds and injustice, that's why body will suffer in grave. It's mean the soul is peace, peace is inside bodysoul peace and body peace is two different things body peace is lies in worldliness while soul peace is lies inside you, if you doing something and yours inside is not agree so don't do you will be in peace forever.
Why we are suffering??
Why we are crying?? Everything we have but still we are unhappy?? Some regrets lies insides why? Because we mostly focus on our body and leave the soul to suffer in this world and in this life but the soul will leave one day forever and will leave our body to remorse and suffer, but after that we can't do anything, and at that time have no back space to return time so we have to look in our inside peace is lies within one's self..