Source: The Maryknoll Catholic Dictionary
Pray for our missionaries throughout the world; the fingertips of our faith.
Mission in its broadest sense refers to any commission or power for carrying out an assignment. In theology, "mission" or "sending forth" has its principle in the Trinity; the Father sending forth the Son into the world.
Christ in turn sent forth the Apostles to "preach the gospel to every creature."
In this sense of "preaching the gospel," mission may be described as preaching to Christians to stir up the grace that is in them, or as a preaching to pagans to announce the good news of salvation. The latter is usually termed "foreign" mission, since historically Christianity developed in Western civilization, and countries not in the geographical sphere of this civilization were considered "foreign."
The missionary, however is an emissary of Christ not of the continent, a country, a culture or of commerce.