Does the Law Still Apply to Christians?

Question:

Why do Christians say that the Old Testament Law no longer applies, when Jesus said that it does?
I know that a lot of Christians will often say that all of the laws in the old testament (Leviticus, Deuteronomy) no longer applied because "that was the old covenant, and Jesus is the new covenant."

But in Matthew 5:17-18 Jesus clearly states that this is not true, and that the OT laws apply until the end of the world. So where does the whole idea that they no longer apply come from?
Here is the passage I am talking about, you can see that Jesus clearly says that the laws apply until the end of the world, not when he dies: "Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. I tell you the truth, until heaven and earth disappear, not the smallest letter, not the least stroke of a pen, will by any means disappear from the Law until everything is accomplished.

My Reply:
Yes, Jesus is the fulfillment of the Law, and yes, the Law still applies, even for us Christians, but it is no longer to be seen as that which makes us right with God.

Paul said that the Law was used as a means of showing us our sin...the mirror that reflects only the truth. It was meant as a "nanny" (Paul's words in the Greek), something to bring us up as God's people and to prepare us for Christ's first arrival.

Also, keep in mind of the target audience and background of Matthew, as well as the Law:
1) Target audience of Matthew's Gospel = Jewish Christians
2) The Law was given after the Jews had lived in Egypt for over 500 years. They'd grown up and formed their culture according to that of the Egyptians. God was saying, 'your my people, and therefore need to begin to behave differently, as I am different'. That's what the Law was supposed to do, with the main goal of preparing them for the coming of their King, Jesus.

So the Law today in the lives of Christians: Though we don't focus on the Law so much as do the Jews in terms of like, 2 materials of clothing or celebrating lunar holidays for instance, knowing the Law still shows us our sin, bringing us to repentance, as it was meant to do in the beginning. It still applies, for it's the instructions of training for what it means to be God's people...Holy
.

---Pastor Andy