[27] Peace I leave with you; my peace I give to you. Not as the world gives do I give to you. Let not your hearts be troubled, neither let them be afraid.

(John 14:27 ESV)

Jesus has been talking about his impending departure, Judas' betrayal, Peter's denial. The disciples are understandably concerned - it looks like the wheels are falling off this mission. Jesus comforts them by promising the Holy Spirit.
Part 1 - help
Part 2 - family 
Part 3 - teacher 
Jesus gives us peace - Shalom - not just the absence of conflict but positive fulfillment, everything as it should be. That peace is a gift. It's not like the peace that the world offers which is, at best, temporary "peace and quiet". Our greatest conflict is not in our circumstances, it is between us and God - and that is where Jesus has brought peace. Once that relationship has been reconciled we can experience peace in the middle of unpeaceful circumstances.