Rahab's Bright Red Cord
Jos 2:18 If, when we come into the land, you put this cord of bright red thread in the window from which you let us down; and get your father and mother and your brothers and all your family into the house;
19 Then if anyone goes out of your house into the street, his blood will be on his head, we will not be responsible; but if any damage comes to anyone in the house, his blood will be on our heads.
The land of Jericho was about to be judged by God through the nation Israel. But there was one person there who was promised deliverance from the judgment---the harlot Rahab.
The Israelite spies promised Rahab that she would be spared and everyone with her in the house where she would bind the bright red cord. They guaranteed her safety with their lives: "if any damage comes to anyone in the house, his blood will be on our heads."
All Jericho will be destroyed. But there was one place of safety and salvation in that place. And that is in the house of Rahab where the bright red cord was tied. Israel did come and destroy Jericho EXCEPT in that very place of safety.
In the same way, God is going to judge this place (the world). And there is only one place of safety. It is in the place where the Savior was "tied" and "bound," so to speak, to a cross where He shed His blood---the cross of Calvary.
Anyone who will hide himself by trusting in what Christ did on the Cross will be saved.