Peace I leave with you; My [own] peace I now give and bequeath to you. Not as the world gives do I give to you. Do not let your hearts be troubled, neither let them be afraid. [Stop allowing yourselves to be agitated and disturbed; and do not permit yourselves to be fearful and intimidated and cowardly and unsettled.]
Just before He was to go to the cross, Jesus told His disciples He was leaving them a gift—His peace. After His resurrection, He appeared to them again, and the first thing He said to them was, Peace to you (See John 20:19)! To prove to them who He was, He showed them His hands and His side and then said to them once more, Peace to you (v. 21)! Eight days later, He again appeared to them, and again His first words to them were, Peace to you (v.26)!
Obviously Jesus intends for His followers to live in peace despite what may be going on around them at the time. What He was saying to His disciples—and to us—is simply, “Stop allowing yourselves to be anxious, worried, and upset.”
In Psalm 42:5, the psalmist asks, Why are you cast down, O my inner self? And why should you moan over me and be disquieted within me? Hope in God and wait expectantly for Him, for I shall yet praise Him, my help and my God.
When we begin to become worried, upset, cast down or disquieted within, we need to hope in God and wait expectantly for Him, Who is our Help and our God.