Acts 15:30-35 :
So, when they were sent off, they came to Antioch. Having gathered the multitude together, they delivered the letter. When they had read it, they rejoiced over the encouragement. Judas and Silas, also being prophets themselves, encouraged the brothers with many words, and strengthened them. After they had spent some time there, they were sent back with greetings from the brothers to the apostles. But it seemed good to Silas to stay there. But Paul and Barnabas stayed in Antioch, teaching and preaching the word of the Lord, with many others also.
The letter from Jerusalem encouraged the Gentile brothers. This is evidence that it wasn’t a letter that put them under a legal obligation. Legal obligations are not very encouraging and lead to a loss of joy. It’s like the difference between getting charged for new taxes and receiving a gift. In this case the brothers were encouraged and decided to send back greetings to the apostles. It must have been an amazing time for the early believers. They all realized that they were free from following the law that they could never measure up to. The law only showed them how bad they were but was never able to help them be good. Now, they were free to be good as the Holy Spirit encouraged them.
Silas, Paul and Barnabas must have really been enjoying their ministry. They had already “spent some time” there and they decided to stay, “teaching and preaching the word of the Lord.” God is able to give us a true, heart felt, desire for the ministry that He asks us to do.