Philippians 4 has two well-known parts to it. Verses 6-7 tell us not to be anxious about anything, but through prayer, petition, and thanksgiving, present our requests to God, and the peace of God which passes all understanding, will guard our hearts and our minds in Christ Jesus.
And then in v.11-13, Paul says he has learned the secret of being content - whether he is in plenty or in want, whether he is well-fed or hungry - he has learned to be content in all circumstances.
Many people today are anxious. Many people today do not feel content. But, Paul is telling us that if we have a relationship with God through Jesus Christ, our anxiety can be replaced by the peace of God, and we can learn to be content, no matter what is going on around us.