Ephesians 2:11-22;

Paul says something here, that we need to hear:

Those people on the streets, those people on those shows, singing that music, in that bar, in that night club, that teenager with the child... You were there once. You have only one difference from them, you have Jesus. Why do I like this little bit? Because it is humbling, we realize, we are not above them. But, we have been brought near to Christ' blood.

Now, where Paul says that Christ is our peace, in this context he does not mean peace in troubled times (though Christ is our comfort and peace in those times).
At the fall, peace between God and man was destroyed, the Priest had to go to God for us. In fact, in the temple there was a physical barrier that separated where the Priest' could go and where "commoners" could not.
Christ restored this peace, broke that middle wall, and gave us direct relation to God. Christ is our peace, with Christ, we are "cool" with God.

 To God, we are no longer strangers and foreigners, we are citizens and Saints... in the house of God. And we, in our faith have been built by the Apostles, Prophets, with Christ as our cornerstone.

Christ is our cornerstone, we are built, like a house, in our faith, with the Gospel (the Apostles and Prophets)
 as the materials, so that we can be a dwelling place for the Holy Spirit.

Thanks for reading,

John Mark,