Red Sea and Dry Ground

Exodus 14 is one of my favorite chapters in the Bible; I like it because it took such faith for the Israelites to trust God, when they were in the Red Sea and the Eqyptians were pursuing them, and God allowed the Egyptians to enter the sea after the walls of water had been held back by God. I always wonder why God didn't kill the Egyptians on the shore. He could have done that - but it wouldn't have taken so much trust in God. Today, I'm wondering why God doesn't sell the house we have been asking him to sell. Why he doesn't sell it immediatly. Why make us wait. Yet, perhaps it's a process of trust for me as well.