One of the greatest discouragements to our evangelism is the relatively sparse response we experience even when we preach the gospel faithfully. This causes us either to question ourselves, or more dangerously, to question the truth and power of the gospel itself.

The discouragement we feel is not helped when we compare our experiences with the records of other times in Church history, or with the way that God is at work in other places in the world.

Our natural tendency to discouragement is one of the reasons why the book of Acts is such an encouragement. Acts is not so much a manual for evangelism but rather a record of the way in which the gospel message advanced to penetrate the various cultures of the Roman Empire, whether Jewish, Greek or Roman.

As we read the book we see the same fundamental gospel message of Jesus, the resurrected Lord and Messiah, being contextualised and preached to different cultures in different ways, with the same call to repent and trust in Jesus as Lord before he returns in judgment.

Acts clearly teaches us that the same gospel, preached by equally powerful and gifted evangelists, will meet with varying levels of response. In some places there is a great response – thousands turn to the Lord and are baptised. In others situations, only a few people believe.

The reason is neither connected with the preacher nor the message that is preached. God is sovereign in evangelism, both over when and where the gospel is preached and over the fruits of that preaching.

Nowhere is this clearer than in the final section of the book, which records Paul's arrest in Jerusalem, his various trials before the Jewish and Roman authorities, and his subsequent journey to Rome to stand before Caesar.

This narrative seems to be given a disproportionate amount of attention in Acts, but it is crucial to the message of the book. It highlights the way that Paul walks in the footsteps of Jesus, recapitulating his own arrest, unjust trial on false charges and willing submission to death. However it emphasises especially the sovereignty of God, who has had as his purpose all along that Paul should stand before the Roman Emperor and testify that Jesus is the true Lord of the world, and the divine king whose reign will ensure for eternity.

As the events unfold Paul has multiple opportunities to testify to the gospel. He is able to testify to the crowds at the temple (21:37-21), to the Sanhedrin (22:30-23:11), before Governor Felix (24:1-27), and before Governor Festus, King Agrippa and Queen Bernice (25:13-26:32). He also had an amazing opportunity to engage in frequent one-to-one evangelism with Festus and his wife Drusilla (24:24-26).

Paul saw his trials as an opportunity not just to defend himself, but to persuade his accusers to believe the gospel. He was quite open with King Agrippa that this was his aim and purpose (Acts 26:28-29). However what is so striking about this section of Acts is that none of those who hear Paul proclaim the gospel are converted. They conclude that Paul is innocent of the charges brought against him, but they do not repent and believe in the Jesus he has proclaimed.

This ought to bring us comfort in our own evangelism. Paul was faithful in preaching Christ yet his preaching did not produce the fruit of conversion. It was the same when he went to Rome and stood before the Emperor. Nero was not converted by Paul's "evidence". Paul did not consider that he had failed, nor did he question the truth or power of the gospel.

God's greatest purpose in evangelism is ultimately that he will be glorified by the proclamation of the truth about his Son the Lord Jesus. Our task is to proclaim him, urging others to respond in repentance and faith. This is especially important as we preach Christ to those who hold positions of power in the world. It is perhaps unsurprising that the rulers of this age are less responsive to the gospel, given that God delights to choose the lowly and despised to shame the noble and the strong.

Acts reminds us that our task is to preach Christ wherever, and to whomever, God in his sovereignty directs us. We must expect that the gospel will meet with varying levels of response, and sometimes with no response at all. If we have proclaimed Christ faithfully we have not failed, and nor has the gospel. God has been glorified by the public declaration of the truth about Jesus.

Even when there is no obvious response by way of conversions to the preaching of the gospel this does not mean that there has been no fruit at all. As Paul writes in Philippians, the effect of his imprisonment and testimony in Rome was to embolden others to preach the gospel more boldly:

"Now I want you to know, brothers and sisters, that what has happened to me has actually served to advance the gospel. As a result, it has become clear throughout the whole palace guard and to everyone else that I am in chains for Christ. And because of my chains, most of the brothers and sisters have become confident in the Lord and dare all the more to proclaim the gospel without fear." (Philippians 1:12-14)

Acts teaches us that faithfulness is the measure of success in gospel ministry, not numbers. This does not take away from our responsibility to make every effort to contextualise the gospel and to preach it as persuasively and winningly as we can. But it does liberate us from the danger of discouragement when our faithful ministry seem to have produced so little direct response.

John Stevens is National Director of the Fellowship of Independent Evangelical Churches (FIEC) and blogs regularly at http://www.john-stevens.com/ .