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Study Dictionary
Peacemaker
PEACEMAKER [ISBE]
PEACEMAKER - pes'-mak-er: Occurs only in the plural (Mt 5:9, "Blessed are the peacemakers (eirenopoioi): for they shall be called sons of God" (who is "the God of peace")). We have also what seems to be a reflection of this saying in Jas 3:18, "The fruit of righteousness is sown in peace for (the Revised Version margin "by") them that make peace" (tois poiousin eirenen). In classical Greek a "peacemaker" was an ambassador sent to treat of peace. The word in Mt 5:9 would, perhaps, be better rendered "peace-workers," implying not merely making peace between those who are at variance, but working peace as that which is the will of the God of peace for men.W. L. Walker
Also see definition of "Peacemaker" in Word Study