Why was God about to kill Moses in Ex. 4:24-26?
Exodus 4:24-26 24 And it came to pass on the way, at the encampment, that the LORD met him and sought to kill him. 25 Then Zipporah took a sharp stone and cut off the foreskin of her son and cast it at Moses' feet, and said, "Surely you are a husband of blood to me!" 26 So He let him go. Then she said, "You are a husband of blood!" -- because of the circumcision.
Given that God let Moses go after his son was circumcised, it appears that the issue was circumcision. Zipporah was very obstinate about this matter and so it is realistic to assume that Moses and Zipporah had a conflict about their son and if he should be circumcised. This is the point in time when the conflict is resolved. God threatens Moses with death, and while the issue seems to have been debated, Zipporah concedes and circumcises their son, even though she did it in protest.
Moses was not raised as an Israelite, but he would have been circumcised as he was born in the household of his parents and kept there for quite some time. Circumcision was a very important covenant between God and Abraham (Genesis 17:7-14). The land that Moses was about to lead the children of Abraham into was promised in conjunction with the covenant of circumcision. Therefore, it would be expected that the leader of the people into the land would also obey the covenant.
Why God would choose to confront Moses and threaten to kill him is difficult to say. God established the penalty already that Moses was to be cast out from the people and not that he was to be put to death. This was a unique circumstance however where God was wanting Moses to be restored to the people, such that he could lead them into the promised land. It could be therefore that God decided to threaten Moses with death if he was not willing to obey the covenant in this case because Moses would have had a significant problem integrating with the children of Israel if he didnít circumcise his son. We donít know if God was going to execute the judgment or not. If He was really going to do so, He would not have delayed long enough for Zipporah to perform the circumcision.
Moses would have been responsible to ensure the circumcision was performed. I believe this is why Zipporah threw the foreskin at his feet in a type of tantrum. He probably did not circumcise his son in order to maintain peace in his home before, but now he is confronted with his new responsibilities to Israel. It could be that God was threatening Moses to get at Zipporah and inspire her to allow the circumcision to take place. God could have found a new person to lead the children of Israel out of Egypt, but Zipporah would have found it more difficult to find a new husband.
It is interesting to note that God selected Moses to be His instrument before Moses circumcised his son. I believe this is an excellent example of how God will work with us in the midst of our sinfulness. God didnít wait for Moses to become righteous. God worked with Moses on the way and provided the inspiration necessary to be effective in the task He already gave Moses to perform.