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.
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?