St. Barnabas was extremely fruitful for God's kingdom. This makes him one of the greatest saints, for we are known by our fruits (Lk 6:44).
St. Barnabas bore fruit in risking his life to accept St. Paul (see Acts 9:27). Paul eventually became an apostle, the writer of many books of the New Testament, and one of the first Christian missionaries in addition to Barnabas.
St. Barnabas bore fruit in forming Antioch, the first missionary church. He had the daring and wisdom to seek out Paul to teach the church of Antioch for a year (see Acts 11:25-26). This church matured to the point that it heard and obeyed the Holy Spirit's command to send forth the first Christian missionaries (see Acts 13:2).
St. Barnabas bore fruit in John Mark, his cousin. After John Mark quit the first Christian missionary journey, Barnabas argued with Paul to have John Mark reinstated for the second mission (see Acts 15:37ff). Barnabas' support of John Mark eventually bore fruit when Mark wrote the second gospel.
St. Barnabas had a deep influence on the formation of the early Church, the New Testament, and the first missionary outreach of the Church. He is among the most fruitful Christians ever. Hear and obey the Lord as Barnabas did.