John Chrysostom preaches on the importance of rejoicing in the Lord always, even in the midst of trials and suffering, emphasizing the peace that comes from prayer, supplication, and thanksgiving to God. He contrasts the teachings of Christ and Paul regarding mourning and laughter, highlighting the deeper spiritual meanings behind them. Chrysostom encourages believers to focus on virtuous and honorable things, to be at peace with all, and to imitate God by being peacemakers, as this leads to freedom from sin and a closer relationship with God.