This is an article that I read from John Piper. Maybe it will help you with some questions or doubts that you've had.
Why Are People Reluctant to Go into Missions?
When I spoke at Missions in the Main Hall Sunday night, I tried to give a biblical response to possible obstacles that are in the way for some people that may keep them from moving forward toward missions. My prayer is that God would use these responses to call more of you to go. Here are eight objections and a biblical response.
1. "I am not smart enough."
"Where is the one who is wise? Where is the scribe? Where is the debater of this age? Has not God made foolish the wisdom of the world? For since, in the wisdom of God, the world did not know God through wisdom, it pleased God through the folly of what we preach to save those who believe." (1 Corinthians 1:20-21)
"Consider your calling, brothers: not many of you were wise according to worldly standards, not many were powerful, not many were of noble birth. But God chose what is foolish in the world to shame the wise." (1 Corinthians 1:26-27)
2. "My body and my personality are not strong enough."
"But we have this treasure in jars of clay, to show that the surpassing power belongs to God and not to us." (2 Corinthians 4:7)
"[Christ] said to me, 'My grace is sufficient for you, for my power is made perfect in weakness.' Therefore I will boast all the more gladly of my weaknesses, so that the power of Christ may rest upon me. For the sake of Christ, then, I am content with weaknesses, insults, hardships, persecutions, and calamities. For when I am weak, then I am strong." (2 Corinthians 12:9-10)
3. "I am not a good speaker."
"Christ did not send me to baptize but to preach the gospel, and not with words of eloquent wisdom, lest the cross of Christ be emptied of its power." (1 Corinthians 1:17)
"Moses said to the Lord, 'Oh, my Lord, I am not eloquent, either in the past or since you have spoken to your servant, but I am slow of speech and of tongue.' Then the Lord said to him, 'Who has made man's mouth? Who makes him mute, or deaf, or seeing, or blind? Is it not I, the Lord? Now therefore go, and I will be with your mouth and teach you what you shall speak." (Exodus 4:10-12)
4. "I am afraid of the horrors I read about in the newspapers."
"Be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour. Resist him, firm in your faith, knowing that the same kinds of suffering are being experienced by your brotherhood throughout the world. And after you have suffered a little while, the God of all grace, who has called you to his eternal glory in Christ, will himself restore (katartisei—"mend" or "repair" your horribly disfigured body when the lions in the coliseum are through with you), confirm, strengthen, and establish you." (1 Peter 5:8-10)
5. "I am afraid I won't be fruitful"
Your responsibility is not to be fruitful but to be faithful. "And said, 'The kingdom of God is as if a man should scatter seed on the ground. He sleeps and rises night and day, and the seed sprouts and grows; he knows not how. The earth produces by itself, first the blade, then the ear, then the full grain in the ear. But when the grain is ripe, at once he puts in the sickle, because the harvest has come." (Mark 4:26-29)
"I planted, Apollos watered, but God gave the growth. So neither he who plants nor he who waters is anything, but only God who gives the growth." (1 Corinthians 3:6-7)
6. "There is plenty to do here."
True, but there is a division of labor and God calls some to MISSIONS, not just evangelism. The difference is seen in Romans 15:19-24: "So that from Jerusalem and all the way around to Illyricum I [Christ] have fulfilled the ministry of the gospel of Christ; and thus I make it my ambition to preach the gospel, not where Christ has already been named. . . Now, since I no longer have any room for work in these regions . . . I hope to see you in passing as I go to Spain."
How could Paul say there was no room for work when there were millions in that region to be evangelized? Because evangelism is not missions.
7. "I am not married."
The best spouse is found on the path of obedience. "An excellent wife [or husband!] who can find? She [and he!] is far more precious than jewels" (Proverbs 31:10). The finding is exceedingly hard. It will happen on the road of obedience.
8. "I fear that when I get there it might turn out I made a mistake and will come home with shame."
Which is worse, shame for having endeavored to follow Christ in missions, or fear to venture? Shame before others for making a mistake will not hurt you; it will humble you and can make you more useful in a new situation. But fear will make you useless everywhere.
Consider Ecclesiastes 11:4 and what it says about risk: "He who observes the wind will not sow, and he who regards the clouds will not reap." Meaning: without taking the risk of sowing when the seed might be blown away and reaping when the rain might ruin the harvest, you will starve.
Oh, how precious is the freeing word of God,