The men encountered some people who were very stuck in the old laws and wouldn't budge. They believed they had to be circumcised according to the law of Moses. Paul and the other man were quick to explain how through the blood of Christ they were saved and nothing else. They were dismissed and told to go to the apostles in Jerusalem and see what they said. When they arrived there they were received by the church in a different way than usual. They listened to what the men had said but the Pharisees stood up and said that they still needed to be circumcised and follow the law of Moses. They were not supported in the way they should have been.
After waiting awhile Peter stands up and speaks what is on his heart. To put it simply he tells them that they as Jews have not done well in keeping the laws so why should the force strict principles on the Gentiles. They needed to look no farther than the truth of salvation and that was all they needed.
James, the brother of Jesus, stood before the people and stated that the old laws of Moses were holding them down and causing strife. They should be concerned with the eating and moral customs.This approach was almost like a compromise for the leaders so they would be quited.
After Paul had had some time to be refreshed in Antioch he approaches Barnabas and says they need to head out again. Barnabas was in full agreement but wanted to take Mark with them this time. I don't know if it was a clash of personalities or that he thought Mark wasn't ready but Paul kept insisting that he not join them. Both men being set in there ways decided it would be best if they separated. At first I thought it was sad that the two men couldn't agree and join together but the I thought of how these two strong men would be able to reach out to more people if they were split up.
Barnabas along with Mark sail to Cyprus and after this point are not mentioned again in Acts. Paul immediately sends out for Silas who had proven himself a faithful disciple. He accepted and they headed to Asia Minor. I studied where Silas was a Roman citizen and that this would help out in their travels to avoid trouble with authorities.