What about missionaries? Does God want you to be a missionary?

How beautiful on the mountains are the feet of the messenger who brings good news, the good news of peace and salvation, the news that the God of Israel reigns! (Isaiah 52:7)

This is a beautiful missionary message of deliverance for Jerusalem. It was spoken in the context of Zion being taken captive by Assyria.

The prophet sees the [missionary] messenger come bounding over the mountains of Judaea, to bring the news to Jerusalem that her deliverance is come (ver. 7). The angelic watchers sing with joy (ver. 8). The prophet calls upon the waste places of Jerusalem to do the same, and dwells on the greatness of the mercy wrought (vers. 9, 10). Finally, he exhorts the exiles to avail themselves of the permission to quit Babylon, and prophesies that they will go forth in peace, without hurry, under the guidance and protection of God  Pulpit Commentary

This is a beautiful prophecy of immediate release from the bondage of Assyria and it is a beautiful prophecy of the greater release of the people of God from the bondage of sin.

good tidings—only partially applying to the return from Babylon. Fully, and antitypically, the Gospel (Lu 2:10, 11), “beginning at Jerusalem” (Lu 24:47), “the city of the great King” (Mt 5:35), where Messiah shall, at the final restoration of Israel, “reign” as peculiarly Zion’s God (“Thy God reigneth”; compare Ps 2:6). Jamieson-Fausset-Brown Bible Commentary

That bringeth good tidings, that publisheth peace; that bringeth good tidings of good, that publisheth salvation: these emphatical and repeated expressions are a sufficient evidence that something further and better is here intended than their deliverance out of Babylon, which in itself was but a very imperfect work, and reached at first but to a few of that numerous people, and was attended with many fears, and sorrows, and remainders of their bondage, Ezra 9:8,9 Ne 1:3; and that although that was the beginning of these glad tidings, yet they extended much further, even to the coming of Christ, by whom alone true peace and salvation were procured. –Matthew Poole’s Commentary

Therefore it has an application of a missionary spreading the good news of salvation to a lost and dying people. It is always a wonderful privilege to share the gospel. But, unlike the old hymn, Tell It Again, there are no gypsy boys laying dying alone at the close of the day who can say, “Nobody ever has told it to me!”

But God shows his anger from heaven against all sinful, wicked people who suppress the truth by their wickedness. They know the truth about God because he has made it obvious to them. For ever since the world was created, people have seen the earth and sky. Through everything God made, they can clearly see his invisible qualities—his eternal power and divine nature. So they have no excuse for not knowing God.
     Yes, they knew God, but they wouldn’t worship him as God or even give him thanks. And they began to think up foolish ideas of what God was like. As a result, their minds became dark and confused. Claiming to be wise, they instead became utter fools. And instead of worshiping the glorious, ever-living God, they worshiped idols made to look like mere people and birds and animals and reptiles. (Romans 1:18-23)

But how can they call on him to save them unless they believe in him? And how can they believe in him if they have never heard about him? And how can they hear about him unless someone tells them? And how will anyone go and tell them without being sent? That is why the Scriptures say, “How beautiful are the feet of messengers who bring good news!”
But not everyone welcomes the Good News, for Isaiah the prophet said, “LORD, who has believed our message?” So faith comes from hearing, that is, hearing the Good News about Christ. But I ask, have the people of Israel actually heard the message? Yes, they have:
     “The message has gone throughout the earth,
          and the words to all the world.” (Romans 10:14-18)

The heavens proclaim the glory of God.
     The skies display his craftsmanship.
Day after day they continue to speak;
     night after night they make him known.
They speak without a sound or word;
     their voice is never heard.
Yet their message has gone throughout the earth,
     and their words to all the world. (Psalm 19:1-4)

John himself was not the light; he was simply a witness to tell about the light. The one who is the true light, who gives light to everyone, was coming into the world. (John 1:8-9)

Jesus spoke to the people once more and said, “I am the light of the world. If you follow me, you won’t have to walk in darkness, because you will have the light that leads to life.” (John 8:12)

“But now I am going away to the one who sent me, and not one of you is asking where I am going. Instead, you grieve because of what I’ve told you. But in fact, it is best for you that I go away, because if I don’t, the Advocate won’t come. If I do go away, then I will send him to you. And when he comes, he will convict the world of its sin, and of God’s righteousness, and of the coming judgment. The world’s sin is that it refuses to believe in me. Righteousness is available because I go to the Father, and you will see me no more. Judgment will come because the ruler of this world has already been judged. (John 16:5-11)

If you feel God is leading you to be a missionary witness to your neighbor or someone in a far-flung land, you better obey your conscience. But, please do not let anyone lay a guilt trip on you to abandon your family and head off to the mission field. It has become so bad that it is practically a given that missionary’s have troubled families. The Apostle Paul specifically warned against this…

But those who won’t care for their relatives, especially those in their own household, have denied the true faith. Such people are worse than unbelievers. (1 Timothy 5:8)