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. John 14:27
I have told you these things, so that in me you may have peace. In this world you will have trouble. But take heart! I have overcome the world. John 16:33
Jesus offers his Covenant friends His peace. But He's not talking about peaceful circumstances. If you want to live a peaceful life don't become a Christian. You will still have all the problems of the world plus two others - the tension of church life and the attention of the devil. At times the two may seem to be the same.
In this discourse Jesus lists a whole range of problems which the disciples can expect to face. Having told them they will be hated, persecuted, put out of synagogues, be scattered, even murdered. But, "cheer up!" He says - that is the literal meaning of "take heart".
Jesus offers us peace within the storms of life.
Yes, sometimes He will still those storms as He did on Lake Galilee. But the peace He now offers to us is a deeper peace, the shalom which enabled Him to sleep in the stern of that fishing boat even while it was being tossed and buffeted by the waves (Mark 4:35-41).
But there is a command we must obey in order to obtain this peace. We must not let our hearts be troubled and we must not be afraid.
Paul said this:
Do not be anxious about anything, but in every situation, by prayer and petition, with thanksgiving, present your requests to God. And the peace of God, which transcends all understanding, will guard your hearts and your minds in Christ Jesus. Phil 4:6-7
Peter who had been there in that boat and at the Last Supper put it this way:
Humble yourselves, therefore, under God’s mighty hand, that he may lift you up in due time. Cast all your anxiety on him because he cares for you. 1 Pet 5:6-7
In other words, trust God from within the circumstances, pray about them, and experience the peace of Jesus through them.