Barnabas and Paul successfully evangelized among the "God-fearing" Gentiles who attended synagogues in various Hellenized cities of Anatolia.

[7] Although the date, place, and circumstances of his death are historically unverifiable, Christian tradition holds that Barnabas was martyred at Salamis, Cyprus.

[12] The successful preaching of Christianity at Antioch to non-Jews led the church at Jerusalem to send Barnabas there to oversee the movement.

He found the work so extensive and weighty that he went to Tarsus in search of Paul (still referred to as Saul), "an admirable colleague", to assist him.

At the end of this period, the two were sent up to Jerusalem (44 AD) with contributions from the church at Antioch for the relief of the poorer Christians in Judea.

After recounting what the governor of Cyprus Sergius Paulus believed, Acts 13:9[14] speaks of Barnabas's spiritual brother no longer as Saul, but as Paul, his Roman name.

[13] According to Galatians 2:9–10, Barnabas was included with Paul in the agreement made between them, on the one hand, and James, Peter, and John, on the other, that the two former should in the future preach to the pagans, not forgetting the poor at Jerusalem.

This matter having been settled, they returned again to Antioch, bringing the agreement of the council that Gentiles were to be admitted into the church without having to adopt Jewish practices.

Peter associated freely with the Gentiles there, including eating with them, until he was criticized for this by some disciples of James, as doing so was contrary to Mosaic law.

Paul then stated that Peter and Barnabas "walked not uprightly according to the truth of the gospel" (Galatians 2:14) and upbraided them before the whole church.

For, until some people came from James, he used to eat with the Gentiles; but when they came, he began to draw back and separated himself, because he was afraid of the circumcised.

Paul took Silas as his companion, and journeyed through Syria and Cilicia; while Barnabas took John Mark to visit Cyprus.

A few years later, when Paul was a prisoner in Rome (61–63 AD), John Mark was attached to him as a disciple, which is regarded as an indication that Barnabas was no longer living (Colossians 4:10).

[24] It relates that certain Jews coming to Syria and Salamis, where Barnabas was then preaching the gospel, being highly exasperated at his extraordinary success, fell upon him as he was disputing in the synagogue, dragged him out, and stoned him to death.

[25] Although it is believed he was martyred by being stoned, the apocryphal Acts of Barnabas states that he was bound with a rope by the neck, and then being dragged only to the site where he would be burned to death.

The following day Anthemios found the tomb and inside it the remains of Barnabas with a manuscript of Matthew's Gospel on his breast.

Anthemios presented the Gospel to Emperor Zeno at Constantinople and received from him the privileges of the Greek Orthodox Church of Cyprus, that is, the purple cloak which the Greek Archbishop of Cyprus wears at festivals of the church, the imperial sceptre and the red ink with which he affixes his signature.

[36] "Photius of the ninth century, refers to some in his day who were uncertain whether the Acts was written by Clement of Rome, Barnabas, or Luke.