It is helpful to make distinctions between full-time missionaries and lay-leaders. We must distinguish between a general practice in a church and a unique, specific gift that God gives to a select few. For example, all Christians should evangelize and witness in some way or another, but only some have the gift of evangelism. All Christians are supposed to give financially, but there are some whom God has entrusted with a special gift of giving. Likewise, Christ gave the Great Commission mandate to the local church so Christians would bear witness to the gospel, but God calls and sends only some specifically as missionaries to make disciples of all nations. ‘The verb apostello has the idea of being sent, and from it comes the word for “apostle” (apostolos), which means “sent one”.’ Our English word, ‘missionary’, comes from the Latin missionem, meaning ‘mission’ or ‘act of sending’, and mittere meaning ‘to send’. Not all Christians can be ‘sent ones’ since the term requires some who are responsible for the sending. We cannot all leave with no one staying behind to support. When Christians claim that all believers are missionaries, this can create excuses for people not to go to the mission field or not to send those with the genuine missionary call. Why prioritize one over another if we all bear the same title and role?
What separates a missionary from the common Christian? What does it mean to be called? So many young people have wondered, ‘What exactly is a missionary call and how can I know I have that call?’ Kane says that some people claim the missionary must have a ‘Macedonian call’ like Paul in Acts 16:9-10. Kane claims that such a call often derives from visions, dreams, voices, and the like. According to this viewpoint, without the existential experience it is impossible to receive a missionary call. Thus, every Christian should seek out such an experience and wait until it comes.
Christ gave the Great Commission mandate to the local church so Christians would bear witness to the gospel, but God calls and sends only some specifically as missionaries to make disciples of all nations.
The second common viewpoint, according to Kane, is similar to the above-mentioned claim. It says that all Christians are missionaries, so no call of any kind is required. Missionary work is no different from any other Christian service. An adherent to the first position may wait around too long, waiting for a vision. An adherent to the second position may go overseas and then return home disillusioned and discouraged. These two common approaches are foreign to the matter-of-fact style of bygone eras, such as the blunt reasoning of the Scottish missionary to the Mongols, James Gilmour (1843–1891):
I thought it reasonable that I should seek the work where the work was the most abundant and the workers fewest. . . . I go out as a missionary . . . that I may obey the command of Christ, ‘Go into all the world and preach.’ . . . My going forth is a matter of obedience to a plain command; and in that place of seeking to assign a reason for going abroad, I would prefer to say that I have failed to discover any reason why I should stay at home.
Consider the Apostle Paul and how he appealed to his burden to take the gospel to Spain. After preaching the gospel from Jerusalem all the way to Illyricum, Paul claimed, ‘I have fulfilled the ministry of the gospel of Christ’ (Rom. 15:19). Paul apparently interpreted his ministry of sowing gospel seeds and planting gospel churches as fulfilling his missionary calling. He went on to describe the impulse of his unique missionary calling, ‘And thus [after fulfilling the ministry of the gospel of Christ all the way from Jerusalem to Illyricum] I make it my ambition to preach the gospel, not where Christ has already been named, lest I build on someone else’s foundation’ (Rom. 15:20). Clearly, Paul saw his missionary function as that of a pioneer. His heart burned to bring the gospel to the unreached, and in his worldview, the remotest part of the known world was Spain, to which he endeavored ultimately to go (cf. Rom. 15:24, 28).
However, there is a short yet essential verse in the middle of Paul’s description of his ambition to take the gospel to Spain, not wishing to preach where Christ had already been named. After highlighting his consuming ambition, to what does he finally appeal? His spectacular experience on the road to Damascus? A prophetic word? A vision of heaven? Wanderlust and adventure? Colorful Spanish culture and tapas cuisine? No. He appeals to sacred print. An ancient scroll, ‘As it is written, “Those who have never been told of him will see, and those who have never heard will understand”’ (Rom. 15:21). Paul contended that the text of Isaiah 52:15 was the ground for his controlling ambition to take the gospel to the unreached. Do not skim over the inherent conviction of Paul’s short transitional phrase from describing his gospel ambition in verses 18-20 to quoting Isaiah’s prophecy: But as it is written. Of all missionaries, Paul could have legitimately cited a vision from Jesus Himself. He could have easily referenced his encounter with Christ on the Damascus road or his heavenly vision. Yet the roots of Paul’s missionary impulse emerged out of the written Word as sufficient, compelling, and authoritative. It was the Scripture alone that commanded Paul’s missionary allegiance.
 C. Gordon Olson, What in the World is God Doing? (Cedar Knolls, NJ: Global Gospel Publishers, 2003), 10.
 Consider what Olson aptly states: ‘All Christians are to be missionary-minded in obedience to the Great Commission, but not all Christians can be missionaries in the proper biblical sense of the word.’ Olson, What in the World is God Doing?, 12.
 J. Herbert Kane, Life and Work on the Mission Field (Grand Rapids: Baker, 1990), 1.
 Richard Lovett, James Gilmour of Mongolia (London: Religious Tract Society, 1892), 42-3.
 Modern-day Dalmatia on the eastern shore of the Adriatic Sea in Croatia.