How, for example, were the laws against cattle breeding, sowing fields with two kinds of seed, and wearing clothes of mixed linen and wool fulfilled in Christ?
And were the laws against homosexuality also fulfilled in Christ, and hence don't need to be followed any longer? How about the laws against defiling your daughter by making her a prostitute? Fulfilled? Don't need to be followed anymore?
The law hasn't changed. Those are God's standards for us, they always have been. The requirement to live by them no longer applies but that doesn't mean the truth of them has changed.
If these laws remain true, why aren't we required to live by them? Because they aren't "as true" today?
They're just as true today. Just don't confuse regulations about living for the benefit of the health and safety of the people and animals with the moral law.
The Law was put in place to show us God's standards and that we fall short of them. They were never issued so that by following them, we could *earn* salvation. We aren't required to live by them because salvation is through faith, not the works of the Law.
Galatians 3: 10-13 All who rely on observing the law are under a curse, for it is written: "Cursed is everyone who does not continue to do everything written in the Book of the Law." Clearly no one is justified before God by the law, because, "The righteous will live by faith." The law is not based on faith; on the contrary, "The man who does these things will live by them." Christ redeemed us from the curse of the law by becoming a curse for us, for it is written: "Cursed is everyone who is hung on a tree."
Gal 3:24 & 25 So the law was put in charge to lead us to Christ that we might be justified by faith. Now that faith has come, we are no longer under the supervision of the law.
Many of those laws were put into place to protect the people. Sowing fields with two kinds of grain, for example, could result in hybrids which could be infertile. The people could starve if they didn't get a crop. I don't recall any laws about cattle breeding, although oxen were not to be unequally yoked with other animals to prevent animal cruelty.
Beats me why linen and wool shouldn't be mixed.