Why Does God Do What He Does?

Exodus 4:22-26

22 Then say to Pharaoh, ‘This is what the LORD says: Israel is my firstborn son, 

23 and I told you, “Let my son go, so he may worship me.” But you refused to let him go; so I will kill your firstborn son.’”

24 At a lodging place on the way, the LORD met Moses and was about to kill him. 

25 But Zipporah took a flint knife, cut off her son’s foreskin and touched Moses’ feet with it. “Surely you are a bridegroom of blood to me,” she said. 

26 So the Lord let him alone. (At that time she said “bridegroom of blood,” referring to circumcision.)