Romans 8:6 For to set the mind on the flesh is death, but to set the mind on the Spirit is life and peace.
Philippians 4:6-7 do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God. And the peace of God, which surpasses all understanding, will guard your hearts and your minds in Christ Jesus.
Colossians 3:15 And let the peace of Christ rule in your hearts, to which indeed you were called in one body. And be thankful.