24Now a Jew named Apollos, an Alexandrian by birth, an eloquent man, came to Ephesus; and he was mighty in the Scriptures. 25This man had been instructed in the way of the Lord; and being fervent in spirit, he was speaking and teaching accurately the things concerning Jesus, being acquainted only with the baptism of John; 26and he began to speak out boldly in the synagogue. But when Priscilla and Aquila heard him, they took him aside and explained to him the way of God more accurately. 27And when he wanted to go across to Achaia, the brethren encouraged him and wrote to the disciples to welcome him; and when he had arrived, he greatly helped those who had believed through grace, 28for he powerfully refuted the Jews in public, demonstrating by the Scriptures that Jesus was the Christ.
Nearly 2000 years ago, God used people to teach people to teach people to spread the gospel. And in this way, the whole earth now has even more people to tell people to tell people about Jesus. If Paul had not spent time with Pricilla and Aquila, then they probably could not have been so useful to Apollos who then was able to more accurately and eloquently tell about Jesus to many in Ephesus. And likewise, today we all have a role in sharing the gospel as God gives us opportunity. Oftentimes, we cannot see how we could have any significant part in God's story and fail to take our job of sharing the gospel seriously. However, God still uses people to tell people to tell other people through people, places and events of life as seen in Acts 18.