Abstract: Peace is undoubtedly one of the most important needs of human beings which plays a very significant role in their happiness and mental and physical health. Islam religion that has been legislated as a religion based on the nature and needs of human, not only has not ignored humans’ peace but also has considered peace of mind and heart calmness ad the result of this religion which is indeed mention of God. The present query tries to address such issues as mental health, peace and its factors, mental insecurity, calmness of heart and the obstacles of peace from the perspective of the Holy Quran whlie defining the concept of peace and proving its necessity in a descriptive way. It tries to conclude that heart confidence is achieved through remembering God; faith and pray make human prepared for remembering God and gives him relief and peace.