Here's a further example of God's laws still in operation today.
One of God's laws in the Old Testament is to not eat certain foods, and we easily know why now, because they are not healthy for our body. Take shellfish for example. I love crab, lobster, and shrimp. But I know that shellfish are scavengers God created to cleanse the seas. They are not healthy, very, very high in cholesterol that is bad for your veins and heart.
Yet per Apostle Paul, who said whatever is sold in the shambles, that eat, we can eat if we have to. If we get invited to dinner by the non-believer, and they set food before us that God said don't eat, Paul said to eat for The Gospel's sake. Afterall, you're trying to reach the unbeliever with The Gospel.
So did God's laws against eating from His unhealthy list change through Lord Jesus on His cross?
Believe it or not, many brethren think so, that all we need do is pray over that shellfish, and magically it becomes healthy food. Fact is though health science well knows it still isn't healthy for our flesh body. We can get by eating it for years and not see its terrible effect until later in life, but it will still be there.
God's health law didn't scientifically change. It's our liberty in Christ that changed our application of it, that's all.