The Joy of Recollection

"I thank my God in all my remembrance of you" (Phil. 1:3).

A key to Christian joy is to recall the goodness of others.

Though Paul was under house arrest in Rome when he wrote to the Philippians, his mind wasn't bound. Often he reflected on his experiences with the Philippian Christians. As he did, his thoughts turned to prayers of praise and thanksgiving for all that the Lord had done through them.
I'm sure Paul remembered when he preached in Philippi and God opened Lydia's heart to believe the gospel (Acts 16:13-14). Subsequently everyone in her household was saved (v. 15). Surely her kindness and hospitality were bright spots in an otherwise stormy stay at Philippi.
He must also have remembered the demon-possessed girl whom the Lord delivered from spiritual bondage (v. 18), and the Philippian jailer, who threw Paul and Silas into prison after they had been beaten severely (vv. 23-24). Perhaps the girl became part of the Philippian church—the text doesn't say. We do know that the jailer and his whole household were saved, after which they showed kindness to Paul and Silas by tending to their wounds and feeding them (vv. 30-34).
The many financial gifts that the Philippians sent to Paul were also fond memories for him because they were given out of love and concern. That was true of their present gift as well, which was delivered by Epaphroditus and went far beyond Paul's need (Phil. 4:18).
Paul's gratitude illustrates that Christian joy is enhanced by your ability to recall the goodness of others. A corollary is your ability to forgive shortcomings and unkindnesses. That goes against the grain of our "don't get mad—get even" society but is perfectly consistent with the compassion and forgiveness God has shown you. Therefore be quick to forgive evil and slow to forget good.
Suggestions for Prayer

Take time to reflect on some people who have shown kindness to you and encouraged you in your Christian walk. Thank God for them. If possible, call them or drop them a note of thanks. Assure them of your prayers, as Paul assured the Philippians.

If you harbor ill-will toward someone, resolve it quickly and begin to uphold that person in prayer.

For Further Study
Read Matthew 5:23-26; 18:21-35. What were our Lord's instructions regarding forgiveness and reconciliation?