Thanks for the question. I’m actually working on presenting material on the transcendent foundations of law, so this is quite timely!
When you look at the ideas of thinkers like Rousseau, Hobbes, Locke, Mill, and the rest, you begin to see that the basis for why we have law is to bring humanity out of the “state of nature” and into the “state of civilization,” What is meant by the “stateof nature” is akin to the “law of the jungle.” In other words, animals live in teh “state of nature,” where might makes right, the weak are killed and eaten by the strong and powerful, and so on. Legal theorists realized that without some kind of group allegiance to something other than sheer power, we’d be doomed to live as animals because human nature is such that we are self-seeking and often victimize people who are at a disadvantage (physically, mentally, emotionally, socially, and so on). So, the idea is that if we all consent to be governed by law, we will be better off.
What this all points to is something specific that God tells us about reality. First, we are created in God’s image, and so there is something about humanity that is objectively different and more valuable than the rest of creation. Unlike lions or chimps, we have the ability to transcend our basic instincts for procreation, violence, and the like. But, we are also quite flawed morally and so we need law to help us overcome those instincts. In other words, the fact that we have law (man-made) simultaneously proves that we are higher than animals but also that we have a sin problem that needs to be controlled (that’s why our laws keep getting more numerous and complicated - our sinfulness is always trying to find “loopholes” to justify our behavior). I find it fascinating that the fundamental and paradoxical truths about humanity from the Bible are simultaneously proven!
God’s law has at least two components. First, there is the overarching moral category. Whether through the Ten Commandments or the 613 other Mosaic laws, there is a moral current that runs. So while the Mosaic law may not apply anymore in the strict sense to believers (Jesus having fulfilled it), the moral law still does apply. As Os Guinness has said, the Mosaic Covenant was the precursor to American constitutionalism. The Hebrews agreed to be bound by God’s law and be faithful to Him. That was the “consent of the governed.” They acknowledged that God’s ways are higher than our ways and consented to be governed by His ways.
Constitutionalism is based on this same idea of the consent of the governed. While we are not a theocracy in America, we hold to the same principal of consenting to be governed by certain principles. And those principles are moral principles (like the inalienable right to life, liberty, and the pursuit of happiness as described in the Declaration of Independence and protected by the Constitution). Those moral principles are only objectively moral if God exists because objective morality exists only if God exists. Otherwise, morality would be subject to human opinion (which changes over time). What is wrong today could be considered right tomorrow. Also, consider the very idea of inalienable rights. A right is inalienable if it cannot be taken away by a human or any group of humans. But if rights are granted to us by humans or human governments, then our rights can be taken away becuase the power to grant is the power to remove. Now, we might argue, people’s rights are taken away all the time when they are wrongly enslaved or killed or what have you. I would argue that in those instances, their rights are not taken away, but are violated. A person who is enslaved still has the right to liberty even in bondage. But that right has been violated. Once they are liberated, that right is fully expressed.
So much more could be said. But the point is this: the very existence of law and our need for it actually points to God. From our specialness in distinction to animals to our sinfulness in needing to be put in check to the fact that we have inalienable rights, all things about the human condition point to a God who wants to restore our original condition, which is to have relationship with Him.
As for favorite resources for Bible questions - oh boy! I have a lot of go-to books. Let me suggest a couple:
When Critics Ask and When Skeptics Ask by Norm Geisler
Hard Sayings of the Bible by Walter Kaiser
The Apologetics Study Bible (which has great footnotes and articles that can help get you started on a topic).
The Bible Answer Book by Hank Hannegraaf
The Case for Christianity (a little handbook by Lee Strobel).
I also use Logos Bible Software, which is a great tool for Bible study in a variety of ways.
I hope this helps!