With Queen Esther, Mordecai had the high honor of proclaiming peace. The peace he announced had been won at high cost. No Jew could be at peace in Persia as long as Haman lived. Just as no peace was possible for any Jew under Haman's sentence of death, so no peace is possible for any man under sin's condemnation of death.
Peace is costly.
Peace with God was purchased when Christ took man's judgement on the cross. Having been justified by faith, the sinner accepts God's peace as a gift. Peace in daily life now becomes possible. There is a personal cost for this. The individual gives up his own way to share his daily concerns with the Lord.