Philippians 4:6-76 Do not be anxious about anything, but in every situation, by prayer and petition, with thanksgiving, present your requests to God. 7 And the peace of God, which transcends all understanding, will guard your hearts and your minds in Christ Jesus. NIV Bible Gateway.com
While in prison, Paul penned precious words about the sufficiency of Christ. We tend to attach the idea of contentment to beach vacation spots and mountain retreats, but the apostle wrote that we are not to be anxious anywhere or at any time because we have the Lord's peace.
Contentment is the believer's birthright. Peace is part of the spiritual fruit that's ours when we trust in the Savior ( Gal. 5:22); it is an inward serenity that passes all understanding (Phil. 4:7). Jesus lived through conflict with a sense of inner quiet, and because of His indwelling Spirit, that remarkable calm belongs to God's children, too. That is important because there are times when we come across a problem that has no earthly solution. In situations like those, we learn that self-sufficiency is a lie. We cannot cope alone, but Christ is all we need.
Here is the flip side of the coin: "'There is no peace for the wicked,' says the Lord" (Isa. 48:22). Modern culture slaps the word wicked onto only the vilest actions and people, but God's definition is much broader. The wicked are those who willfully reject His right to forgive their sins and take Lordship over their life. If you are not a believer, you cannot experience true and lasting contentment.
When we are born again (John 3:3-8), we become children of the living God and rightful heirs to every good thing He has to offer. This includes the deep inner peace and joy that can withstand any trial. What can man do to the one who belongs to the Lord (Heb. 13:6)?
Stanley, Charles F, "Christ: The Key to Contentment," In Touch: Daily Readings For Devoted Living September 2016. Atlanta: In Touch Ministries. page 27.