Ideas about the Kingdom of the Heavens around us and the unity of believers in Christ within it
When Paul wrote his second letter to the Corinthians, he feared he would later come to them and find that they had not repented of their underlying mixed motives and attitudes of self-centered worship and sensual focus. The result would be the same strife and disorder he had reproved in his first letter.
There are those who say that a good Christian should always rejoice because of anything that happens, and must never grieve. These people are wrong. Our instructions are to grieve physical death, and to grieve the sinful condition of our world that leads to it, as God himself does, but to do so in a way that expresses our hope in the resurrection. Do not deny grief, but show hope in grief. Groaning is not a sin.