Barnabas received the gift of the Holy Spirit in the Upper Room with the Disciples. He preached the Gospel with them and witnessed to the name of the Lord Jesus. He had land, sold it, and brought the money and laid it at the Apostles' feet (Acts 4:36, 37). The Apostles honored him for his many virtues and for his honesty.
Three years after St. Paul was converted to Christianity, St. Barnabas took him and presented him to the rest of the Disciples in Jerusalem. St. Barnabas described to the Apostles how the Lord appeared to St Paul on his way to Damascus and attested to his zeal before them. The Apostles accepted St. Paul in their fellowship. The Holy Spirit said to the Disciples: "Now separate to Me Barnabas and Saul (Paul) for the work to which I have called them" (Acts 13:2).
St. Paul and St. Barnabas traveled together to many cities preaching the name of Jesus the Lord. In Lystra, St. Paul healed a certain man without strength in his feet who was a cripple from his mother's womb, who had never walked. Now when the people saw what Paul had done they raised their voices, saying in the Lycaonian language, "The gods have come down to us in the likeness of men!" And Barnabas they called Zeus, and Paul, Hermes, because he was the chief speaker. Then the priest of Zeus, whose temple was in front of their city, brought oxen and garlands to the gates, intending to sacrifice with the multitudes. But when the Apostles Barnabas and Paul heard this they tore their clothes and ran in among the multitude crying out and saying, "Men, why are you doing these things? We also are men with the same nature as you, and preach to you that you should turn from these useless things to the living God, who made the heaven, the earth, the sea, and all things that are in them." And with these sayings they could scarcely restrain the multitudes from sacrificing to them (Acts 14:8-15).
After Paul and Barnabas had traveled together to many cities they were separated from each other. St. Barnabas took with him St. Mark and together they went to Cyprus. They preached there and converted many people to the faith of Christ the Lord and then baptized them. The Jews became very angry for that and they falsely accused them before the Governor of Cyprus. They seized St. Barnabas and brutally beat him, then they stoned him and finally burnt his body.
By this death, his strife was completed and he received a crown of martyrdom. St. Mark came and carried the body, wrapped it, and placed it in a cave in Cyprus. St. Mark then went to Alexandria, Egypt to preach there.