Isaiah 61:1-2 ESV The Spirit of the Lord GOD is upon me, because the LORD has anointed me to bring good news to the poor; he has sent me to bind up the brokenhearted, to proclaim liberty to the captives, and the opening of the prison to those who are bound; (2) to proclaim the year of the LORD's favor, and the day of vengeance of our God; to comfort all who mourn;
In the sermon on the Mount, our Lord Jesus proclaimed,
Matthew 5:4 ESV "Blessed are those who mourn, for they shall be comforted.
That is the essence of the Gospel - the good news - that if you mourn over your sins, Jesus will give you comfort and joy.
In Corinth, there was a brother who committed an act of immorality. The Church rightfully disciplined the erring brother and disfellowshipped him. That action of removing him from the church body caused the brother to realize how wicked his behavior was. He sorrowed over his sin. In 2 Corinthians 2:6-7,11, Paul instructs the congregation to accept back the repentant brother and comfort him before his sorrow became destructive:
2 Corinthians 2:6-7 ESV (6) For such a one, this punishment by the majority is enough, (7) so you should rather turn to forgive and comfort him, or he may be overwhelmed by excessive sorrow.
2 Corinthians 2:11 ESV so that we would not be outwitted by Satan; for we are not ignorant of his designs.
We are called to walk in the joy of the Lord. Sometimes when a Christian sins he/she needs to be removed from the fellowship for their good and for the good of the body. But the removal is not for condemnation but for restoration. Once they have repented then it is our job to seek to restore them back into fellowship and seek to help them to be restored in the JOY OF THE LORD. Those who mourn over their sin will be comforted.