Paul encourages us to stand firm in the Lord and to rejoice in the Lord. He directs us to go to God with our prayers and petitions. This brings the peace of God upon us. Paul also reminds us to do our part – to think about what is true, noble, right, pure, admirable, and praiseworthy. Simply put, he calls us to focus in on the good.
How we look at the world really affects how we live our life. For example, if one spends a lot of time complaining, then life is generally unhappy and what they focus on is dominated by bad thoughts. Loving God and neighbor is a difficult task when all are against you. On the other hand, when one focused on God and all the good in the world, then life is generally happy and content. “Life” still happens but the issues and situations carry less weight because God carries the bulk when we focus on Him.
Also, as we fill our minds with what is true, noble, right, … then there is less time for evil or impure thoughts. As we focus in on the good and God, then He guards our hearts and minds so that our energy and efforts dwell on God and His plans for us in the world. And the God of peace will be with us.
Scripture reference: Philippians 4: 1-9