The only means of acquiring peacefulness of the heart

Having means of ease and luxury is other than having peacefulness of the heart, "Indeed hearts find rest in God's remembrance!”.[ Surah ar-Ra‘d 13: 28] This means that the only means of peacefulness of the heart is Zikrollah (Remembrance of God); but we rely on other causes and are neglectful of the Cause of all causes.