I have just begun to work through this. I wonder if the peace that Christ is offering is that certainty of the resurrection and our place in His kingdom. It seems that one of the themes throughout the New Testament is His call to us to put His kingdom first, Matthew 6:33. Paul picks this up in Philippians 3:20 – 21. We are citizens of His kingdom. We are not primarily citizens of the country that issues us our passport. We are to put His kingdom first.
Our peace, our strength in facing whatever resistance, persecution, suffering, or tribulation may lie in the fact that ultimately it is His kingdom that prevails. Our peace is that we will be secure in that kingdom.