People everyday are judged because of their faith, just as Jesus once was judged for His own. People all around the world are treated differently because of their religious beliefs.
During Jesus' time, He was persecuted for His teachings and some of His followers were killed. Jesus and his followers were very courageous in their teachings, and they even risked their lives to teach the word of God.
Even when some of Jesus' followers rejected Him, He remained strong and forgave each of them regardless of their sins. Even Peter, who rejected Him, became the "rock of the church".
We can be the "living stone" of the church by sharing our faith with others. We can follow Jesus' example of courage by not being afraid to share our beliefs publicly.
Jesus is our cornerstone because although He is always there, many people don't realize that He is until he's gone. Also, He is our support system and our foundation for all creation.