Encourage a failed person and faith of brothers in the church

Acts 15:30-41
The people of Antioch read the letter and were glad for its encouraging message.
Disagreement between Paul and Barnabas, because Mark had deserted them in Pamphylia and had not continued with them in the work. They parted company.
Barnabas took Mark and sailed for Cyprus, but Paul chose Silas and left, commended by the brothers to the grace of the Lord. He went through Syria and Cilicia, strengthening the churches.
A 'sharp argument' about John Mark results in two missionary campaigns instead of one. Barnabas, the 'encourager', not doubt helper his young nephew to make the grade and eventually win Paul's approval.
Silas: Representative of the Jerusalem church. Like Paul, he was a Roman citizen. He traveled with the apostle as far as Beroea and rejoined him at Corinth. Silas was associated with Paul in the writing of 1 and 2 Thessalonians; also with Peter in the writing of his first letter.
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.'
Why?
New believers are easy to be disturbed by the world and personal difficulty, so needed to be encouraged in their faith and help them.
Encourage the young men in the work of God is difficult but good work before the Lord.
Bad record doesn't mean he is unchanged, depends on his mind and works.
Confirm the church and keep growing of the brothers in the church is an important matter.
How?
Not only preach gospel to others but confirm brothers in church is main issue to service in the church.