For you have died, and your life is hidden with Christ in God.
I once saw a movie which I think is a good illustration of this verse.
In the movie an evil magician had deposed a king and taken over his kingdom. A group of rebels was trying to overthrow the magician and restore the rightful king to his throne. One of the rebels managed to get past the guards and run his sword through the magician’s body. To his surprise this didn’t hurt the magician at all. He merely pulled the sword from his body and showed no sign that he had ever been stabbed.
The rebels eventually found another magician who was able to explain the first magician’s invulnerability. He told of a swamp filled with deadly monsters who would kill anyone who met them. In the middle of the swamp was a high tower protected by all kinds of magical devices. In a room at the top of the tower there was a chest containing the heart of the evil magician, still alive and beating. The only way to kill the magician was to overcome the monsters and magical traps and climb the tower and destroy the heart.
Christians have this kind of protection because our lives are with God and anyone wanting to harm us would have to enter the presence of God to do so. The most anyone can do to us is kill our bodies and Jesus said we don’t need to fear anyone who can do no more than this.
The movie isn’t a perfect illustration of our condition because the rebels were able to get past all the obstacles and destroy the magician’s heart while it would be impossible for anyone to penetrate God’s defenses.