John 14:25-29
25 “All this I have spoken while still with you. 26 But the Advocate, the Holy Spirit, whom the Father will send in my name, will teach you all things and will remind you of everything I have said to you. 27 Peace I leave with you; my peace I give you. I do not give to you as the world gives. Do not let your hearts be troubled and do not be afraid.
28 “You heard me say, ‘I am going away and I am coming back to you.’ If you loved me, you would be glad that I am going to the Father, for the Father is greater than I. 29 I have told you now before it happens, so that when it does happen you will believe.
Philippians 4:7
7 And the peace of God, which transcends all understanding, will guard your hearts and your minds in Christ Jesus.