Every Christian should be a missionary whether they do the work of a missionary or not.
Missionaries are passionate about missions. To them, missions is more than just leading someone to Christ. Missions is about getting enough people saved so that they can start a church and then working with that church so that it can stand alone, without the input of the missionary. Then, going on to replicate this process in another work in another place. Sometimes this takes years and other times it takes decades. Suffice it to say that missionaries are heavily involved in all aspects of the work of starting and maturing a church. They are much like a pastor except, pastors stay in their home country and pastors will often stay with the same church even after it is matured.
Missionaries do not want any of the work to be done haphazardly or outside of the authority of the local church. But missionaries would like to see each member of a church get involved in the mission of getting souls saved.
In two days, the entire world knew about the attack on the world trade center in New York City. But the gospel has been shuffling along for 2000 years and still there are people who have never even heard that there is a God. This is a testament to the poor performance of the church in getting the gospel out. In and of itself, this ought to stress the importance of missions to the church. Therefore, any missionary who puts his heart and soul into missions would love to tell the church that they are not getting the job done, they are not placing enough importance on carrying the gospel into all of the world. There are unsaved people in the world who have never even heard about a bible. For the person who daily faces the gospel in “front lines” work of the ministry, there is a severe shortage of Christian soldiers given over to the task of bringing the fight to the enemy. The logistics side of the army is overflowing with personnel, but the battle line is weak; and in some places doesn’t even exist at all.
Each Christian should be a missionary right where God has placed them, but many are not. Most enjoy (emphasis on: enjoy) the benefits that a church has to offer them; and churches are full of benefits because they compete with each other for numbers of people to attend their service instead of someone else’s. The attitudes of Christians are internalized into “how can this church help me and my family,” instead of, “Where does God want me to serve on the battle line of winning souls to Him?”
Some people say they are not called to be a missionary, but this is erroneous. Everyone is called if they are saved! God did not mean for the great commission to apply to some and not to others. Other people may say, “I don’t have the funds or capacity to go to the mission field,” but this too is untrue. God has you right where He wants you. To think otherwise is to attack the omnipotence and omniscience of God, and to think more highly of yourself than you ought to.
Missionaries long to tell church people this, but they cannot for fear of being misunderstood. They would love to inspire you to do more than give, pray or support. They would rather see you so in love with God that you became a fanatic witness for the Lord Jesus Christ.