Our Father in heaven does not change. He is what His people need him to be. Disciplinarian? Yep, but more than anything else, He is our loving Father. I don't see the disconnect.
We see that the generation that came after Joshua were not personally familiar with the wonderous works of their God: ""Now Joshua the son of Nun, the servant of the LORD, died when he was one hundred and ten years old. And they buried him within the border of his inheritance at Timnath Heres, in the mountains of Ephraim, on the north side of Mount Gaash. When all that generation had been gathered to their fathers, another generation arose after them who did not know the LORD nor the work which He had done for Israel." - Judges 2:8-10 NKJV
We hear of his intent when we read Jeremaih, "No more shall every man teach his neighbor, and every man his brother, saying, 'Know the LORD,' for they all shall know Me, from the least of them to the greatest of them, says the LORD. For I will forgive their iniquity, and their sin I will remember no more." " - Jeremiah 31:34 NKJV
He ordered things so that He would be able to impact the lives of His children. They who inhabited the Promised Land were involved in such acts (sacrificing children) so heinious that the land itself is said to have spewed them out. God cautioned His people to NEVER act in that fashion and worked to teach them His ways. When they went to war (there was no avoiding it) they were often instructed to slay every last one and not touch any of the spoils. Were the children of Jacob (who fought with God and prevailed being renamed "Israel" which could be translated as "God-Figher") stubborn and thick headed, yes, we know they were. Am I also stubborn and thick-headed today? Yes, indeed I am.
Much of what transpired between the leaders of the His people, the Priests, Kings, Judges, and Prophets was done by way of example. The men involved in those things noticed the disconnect and wondered and sought to understand and to them it was shown that it wasn't for them only that many things were done but they were being used as an example for us, so we could learn and gain from their experiences. God was cognizant of us, the Gentiles, for instance --when the children of Israel were lead out of Egypt. The bigger picture being painted into their very lives has become a lesson to you and me who wish to depart from sin and walk with our Maker to a city of His making: Heaven. Our heart battles were enacted on the earth for reason --to provide guide posts and lessons for age abidiing time to come.
What's the difference between an agreement written in stone that no man can live up to and one written in the fleshly tablets of our hearts? Jesus authored our heart change and the law that goverened (guided and directed) them brought all men to Him who is our salvation. Nothing was done by chance. Can it be said that the blood of a lamb would appease any except a blood-thirsty God? Yes, because the 1st sacrifices looked in anticipation of the later. Can those things done in the past be likened to our struggles also? Imagine, if you will, a man who came to us and explained like he was explaining to children, the mystery of creation. Now imagine a stubborn child who says, "I don't get it and you can't make me understand."
If one is devoid of understanding and can not grasp the idea, will not even try - begs to be convinced in order to find an audience as he vents? That's how I see it. The thread asks then "How do we respond to arguments like these?" Agree with them. They don't get it. There is nothing any can to do that can make them. They are not and never will be in danger of being convinced against their will, no man is. Let the one who wants to raise his/her head up and accuse God stand by themselves. Don't be part of it.
"Behold, the days are coming, says the LORD, when I will make a new covenant with the house of Israel and with the house of Judah "not according to the covenant that I made with their fathers in the day that I took them by the hand to lead them out of the land of Egypt, My covenant which they broke, though I was a husband to them, says the LORD. "But this is the covenant that I will make with the house of Israel after those days, says the LORD: I will put My law in their minds, and write it on their hearts; and I will be their God, and they shall be My people. "No more shall every man teach his neighbor, and every man his brother, saying, 'Know the LORD,' for they all shall know Me, from the least of them to the greatest of them, says the LORD. For I will forgive their iniquity, and their sin I will remember no more." - Jeremiah 31:31-34 NKJV