"They . . . so spake"
And it came to pass in Iconium, that they went both together into the synagogue of the Jews, and so spake, that a great multitude both of the Jews and also of the Greeks believed. Acts 14:1
You will sometimes hear that it does not matter so much how you share the gospel; what matters is that you share the gospel. And to a certain extent, that is true. But we should beware of making it an absolute, for in some ways it does matter how you do it. For example, it can be done with a wrong attitude and from wrong motives, and we should never want to do that. So the apostle Peter tells us to "give an answer to every man that asketh you a reason of the hope that is in you," but he goes on to say that we are to do it in a certain way, namely, "with meekness and fear, having a good conscience" (1 Pet. 3:15-16).
You see that in the passage before us. Here Paul and Barnabas are in Iconium. This is new territory, so they don't know what to expect. They begin their evangelistic efforts in the synagogue because there people would have been familiar with the Scriptures. But notice what the text goes on to say: it says that they so spake, that a great multitude both of Jews and also of Greeks believed. That word "so" means "in such a manner or way." In other words, the way the apostles preached the word was one of the means God used to bring about the response of faith.
Even so, we want to present God's truth to others in a way that God will be pleased to use our words for his good work in building his church. When you look at Scripture, there are a number of things which marked the speech of the apostles, and which should also characterize ours: such as meekness, fear, and a good conscience. We also see conviction (1 Thess. 1:5), and the love of Christ (2 Cor. 5:14). Often, a lot of listening should precede the opening of our mouths so that we know who exactly we are speaking to (Prov. 18:2).
However, neither should we let the care we have for our words paralyze us from giving an answer. Let us speak, yes, and also let us do it in such a way that honors the truth and the weightiness and the goodness of God's word, and let us do it in absolute reliance upon the God who opens blind eyes and awakens our affections and minds to see the beauty and goodness of God's gospel.