"Joseph, a Levite, born in Cyprus, whom the apostles called Barnabas (son of encouragement), sold a field he owned, brought the money, and turned it over to the apostles." (Acts 4:36f). This is the first mention we have of Barnabas.
His new name fits what we know of his actions. When Saul (or Paul) came to Jerusalem after his conversion, most of the Christians there wanted nothing to do with him. They had known him as a persecutor and an enemy of the Church. But Barnabas was willing to give him a second chance. He looked him up, spoke with him, and brought him to see the other Christians, vouching for him. Later, Paul and Barnabas went on a missionary journey together, taking Mark with them. Part way, Mark turned back and went home. When Paul and Barnabas were about to set out on another such journey, Barnabas proposed to take Mark along, and Paul was against it, saying that Mark had shown himself undependable. Barnabas wanted to give Mark a second chance, and so he and Mark went off on one journey, while Paul took Silas and went on another. Apparently Mark responded well to the trust given him by the "son of encouragement," since we find that Paul later speaks of him as a valuable assistant (2 Tim 4:11; see also Col 4:10 and Phil 24).
Prayer (traditional language)
Grant, O God, that we may follow the example of thy faithful servant Barnabas, who, seeking not his own renown but the well-being of thy Church, gave generously of his life and substance for the relief of the poor and the spread of the Gospel; through Jesus Christ our Lord, who liveth and reigneth with thee and the Holy Spirit, one God, for ever and ever.Prayer (contemporary language)
Grant, O God, that we may follow the example of your faithful servant Barnabas, who, seeking not his own renown but the well-being of your Church, gave generously of his life and substance for the relief of the poor and the spread of the Gospel; through Jesus Christ our Lord, who lives and reigns with you and the Holy Spirit, one God, for ever and ever.Psalm 112