Who is the Lord that I should obey Him?
Pharoah asks the question, "Who is the Lord, that I should obey him?" (Ex 5:2) Characteristic of the Lord, He does not respond directly, but the answer comes with the unfolding of the 10 plagues. Each plague is a response to Pharoah's question; each is more severe than the previous one.
This interplay of Moses and the Pharoah includes many subtlies. As part of the negotiation to allow the people of Israel to go and worship the Lord, Moses insists that all the women, children and livestock accompany the men for a three day retreat. Moses insists on leaving no one and no animal behind. Pharoah assumes trickery, that the people will take off with no surety bond, so does not consent.
As the plagues unfold, the stakes get higher. The Lord has demonstrated himself to Pharoah through the first 9 plagues, yet Pharoah still refuses to believe the Lord should be obeyed.
After the thick darkness of the 9th plague, that affected the Egyptians but not the Israel camp, the Lord through Moses raises the stakes. He requires that Pharaoh himself provide animals for the sacrifice as well bringing their own; "You must also give us have sacrifices and burnt offerings, that we may sacrifice to the Lord our God. Our cattle also must go with us; not a hoof shall be left behind ..." (Ex 20:25-26).
With more experience with the Lord, more was required of Pharoah. In fact, your life is a response to the question, "Who is the Lord that I should obey Him?" You can choose to keep our time, talent and treasure or spend it for Him.
As we have more experience with the Lord, more is required of us. Jesus teaches in Luke 12:48 "Every one to whom much is given, of him will much be required ..." We are called to respond in radical ways to the Lord's work in our lives.