Most people try to avoid persecution, but persecution actually grows the church. Here’s how.
Evangelize or Fossilize
Most of us try to avoid being persecuted, but persecution is actually good and it can cause the church to grow. First of all, the New Testament church was an evangelizing church. They went out into the world as far as they could to bring the good news or the gospel of Jesus Christ. When you share Christ, you’ll be persecuted like Christ. Not to the extent of crucifixion of course, but persecution will come, so no Christian should be surprised when they’re persecuted for their faith in Jesus Christ. The real surprise is if they are never persecuted at all! That tells me something’s wrong, because “all who desire to live a godly life in Christ Jesus will be persecuted” (2 Tim 3:12). By the way, in the Greek, the word all means, all, so every believer will face persecution; at least if they are living “a godly life in Christ.” 
Sowing the Word
Farmers sow their seeds and then wait patiently for rain, fertilizer, and sunshine to take their course. The farmer cannot talk the seed into sprouting. Urge as he or she might, the farmer cannot command the seed to sprout. Some will sprout…some will not, so the farmer’s not responsible for making the seed sprout and grow, however, it is his responsibility to sow the seed. In the same way, we can sow the seed of the Word of God, but we can’t make it take root or keep it from burning up on a rock. We’re not responsible for making the Word take root in a person’s heart…that is God’s responsibility. It’s not our responsibility to save anyone…it is their response to His ability, but it is our responsibility to sow it. Let God determine the harvest. The Bible teaches that there will be those who were never genuinely saved and they fall away on account of persecution. Jesus said they endure “for a while, and when tribulation or persecution arises on account of the word, immediately he falls away” (Matt 13:21). For those who fall away from the church, this too is to be expected. The Apostle John said of them who leave the church: “They went out from us, but they were not of us; for if they had been of us, they would have continued with us. But they went out, that it might become plain that they all are not of us” (1 John 2:19).
Persecution and Growth
I remember hearing about a national Chinese effort to get rid of Christianity once and for all in China. They weren’t willing to kill them because that’d make them martyrs. Instead, they spread them out all across China, putting the greatest distance possible between them. That means they couldn’t associate or worship with other Christians. The Chinese government thought that would be the end of that, but by sending these believers across all of China, they had seeded the gospel of Jesus Christ throughout all of China. By trying to snuff out the church, they had only served to spread it across the entire continent. The same thing happened when “Saul approved of [Stephen’s] execution. And there arose on that day a great persecution against the church in Jerusalem, and they were all scattered throughout the regions of Judea and Samaria, except the apostles” (Acts 9:1). We have to be careful though. We are not to have a martyr’s complex and seek out persecution. That’s not called persecution. That’s being obnoxious.
Scattering the Seeds
In the previous chapter, Saul (later, Paul) condoned the stoning to death of the deacon Stephen. That’s because Saul was on a mission to destroy the church, but what were the results? The Christians “were all scattered throughout the regions of Judea and Samaria, except the apostles” (Acts 9:1), and they brought the gospel of Jesus Christ with them! These fleeing, persecuted Christians spread out into the entire region of Judea and Samaria. That means the entire region of Judea and Samaria heard the gospel, and after the gospel had spread that far, “the church throughout all Judea and Galilee and Samaria had peace and was being built up. And walking in the fear of the Lord and in the comfort of the Holy Spirit, it multiplied” (Acts 9:31). Much of this was the result of persecution. The same thing can happen when you go into your neighborhoods and towns and bring the gospel of Jesus Christ with you.
A Pattern for Growth
If I could put in order how persecution affects the church, I’d be tempted to put it this way:
Persecution spreads the Gospel which grows the church which leads to more persecution, which spreads the gospel, bring more persecution…etc.
When someone or some group is persecuted, people are going to talk about it around town, so persecution leads to a wider exposure of the gospel. A wider exposure of the gospel leads to more witnessing of the gospel, and a wider swath of witnessing for Christ, leads to more people being saved by Christ and the church grows (by God’s good graces). It was in the Antioch Church where Christians “were scattered because of the persecution that arose over Stephen traveled as far as Phoenicia and Cyprus and Antioch, speaking the word to no one except Jews” (Acts 11:19). Now not only had the gospel went into all of Judea and Samaria, now it had gone even further…into “Phoenicia and Cyrprus and Antioch,” so now the Greeks and much of the Roman Empire had opportunity to hear about Christ for the very first time!
If you’ve never been persecuted, then you’ve likely never shared your faith. But if you are being persecuted and faced spiritual attacks, remember, Satan doesn’t waste his time on those who make no difference. The fact is, persecution is growing worse and worse, and will continue to do so up until that very day when Jesus Christ returns. We not only should expect it, but receive it for what it is; a blessing from God (Matt 5:10-12). Persecution can bring growth by bringing attention to the church and to the gospel of Jesus Christ, but this only happens if we’re living a godly life. Those who are not ever persecuted might want to examine themselves to see why. The Bible knows nothing of believers never being persecuted. The Apostle Paul told Timothy that everyone who lives a godly life will, not might, but will be persecuted (2 Tim 3:12). Don’t let these words ring in your ears someday if you’re not saved: “I never knew you; depart from me, you workers of lawlessness” (Matt 7:23), which means “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven” (Matt 7:21). Repent and believe today and you will be saved (Rom 10:9-13).
Here is some related reading for you: Why Persecution is Actually a Good Thing 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible: English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.