I don't agree with "praying for wisdom" in an answer to deciding which BIBLICAL laws to uphold and which to denounce.
The way I see it, you either believe in keeping the law or you don't. And the Bible lets us know that failing to keep one part of the law is failing to keep the whole law. Now, if you believe in keeping the law, and there's a part that you can't keep exactly as written (because of REAL restrictions, such as modern law), then you could use wisdom to adapt that law to modern usage. So while the law won't allow you to stone your disobedient child, you CAN punish them in other, legal ways.
My biggest issue with "praying for wisdom" to determine what to follow and what to ignore is that it leaves too responsibility to a very fallible people. Furthermore, I think most of the time, when it comes to modern Christians, the majority of what we do is because we were taught to do/believe it and have proof-texted it into reason. Most of these Biblical laws are inconvenient and foreign, so we wouldn't keep them even if we were legally and physically able to.
But, that's not just restricted to OT, btw. The Lord has been nudging me to study what it means to be modest. I did a thread on that a while back, and came across it again the other day. I guess He was reminding me. LOL. But yeah, the Bible tells us explicitly that we are to be modest - including in our apparel. And I wouldn't even try to guess how many Black churches actually practice modesty in their apparel. I surely don't. But the Bible says we should. And we ignore it (and redefine the word "modest") for the sake of convenience and carnality.