What did Barnabas urge the new Gentile believers to do when he saw God's grace?
Seeing God's grace among the Gentiles, Barnabas rejoiced and exhorted them all with purpose of heart to cleave to the Lord and maintain their spiritual position. He encouraged these former idolaters, saved by grace, to remain steadfast, and Scripture records that much people were added unto the Lord.
Les explains that Barnabas, a good man full of the Holy Spirit and faith, was glad when he saw God's grace at work in Gentile believers at Antioch. These Gentiles had come out of immoral idolatry, yet God saved them by His grace. So Barnabas exhorted them with purpose of heart to cleave to the Lord—that is, to maintain their spiritual position. Les also stresses that grace is not license; it is greater than any person's sin, so many people were added unto the Lord.