Acts 15. 36 Some time later Paul said to Barnabas, "Let us go back and visit the brothers in all the towns where we preached the word of the Lord and see how they are doing." 37 Barnabas wanted to take John, also called Mark, with them, 38 but Paul did not think it wise to take him, because he had deserted them in Pamphylia and had not continued with them in the work. 39 They had such a sharp disagreement that they parted company. Barnabas took Mark and sailed for Cyprus, 40 but Paul chose Silas and left, commended by the brothers to the grace of the Lord.He did not survive this spiritual/personal conflict. Even though he was in the right!
Perhaps he became bitter (later he chose Peter's wrong doctrine over Paul's correct and "was led astray").
Paul was unaffected.
Barnabas handled it well externally, but poorly internally; Paul was the opposite.
Perhaps he also felt that Paul had himself received great grace and now was not repaying the same - like the servant in Jesus' parable who had a great debt (here murder) but after he was forgiven, would not forgive a tiny debt that he himself was owed (here, desertion).
It is certain that Barnabas may have had brothers and sisters in christ if not actual family who were killed through Saul.
A quarrel stunted his great spiritual potential. He could not achieve further spiritual greatness after this parting.
We must keep our hearts from bitterness even in our doctrinal disputes.
Barnabas was a disciple before Paul. When he was distrusted and shunned by the suspicious disciples, he verified Saul's Damascus road experience so that they accepted him.
But Barnabas took him and brought him to the apostles. He told them how Saul on his journey had seen the Lord and that the Lord had spoken to him, and how in Damascus he had preached fearlessly in the name of Jesus.
Barnabas nurtured Paul for one year. He searched for and discipled Paul so he flourished; did not ignore him and let his gift die out. Deliberate, conscious steps.
The church gave prophetically sending their gift through Paul and Barnabas.
Barnabas recognised the move of God before others did. This was when he saw the new gentile believers and also earlier when he affirmed Saul's vision.
Barnabas was not jealous of other's spiritual prosperity. "He was glad and encouraged them to remain true to the Lord".
"He was a good man, full of the Holy Spirit and faith"
22 Then news of these things came to the ears of the church in Jerusalem, and they sent out Barnabas to go as far as Antioch. 23 When he came and had seen the grace of God, he was glad, and encouraged them all that with purpose of heart they should continue with the Lord. 24 For he was a good man, full of the Holy Spirit and of faith. And a great many people were added to the Lord.
25 Then Barnabas departed for Tarsus to seek Saul. 26 And when he had found him, he brought him to Antioch. So it was that for a whole year they assembled with the church and taught a great many people. And the disciples were first called Christians in Antioch.
27 And in these days prophets came from Jerusalem to Antioch. 28 Then one of them, named Agabus, stood up and showed by the Spirit that there was going to be a great famine throughout all the world, which also happened in the days of Claudius Caesar. 29 Then the disciples, each according to his ability, determined to send relief to the brethren dwelling in Judea. 30 This they also did, and sent it to the elders by the hands of Barnabas and Saul.