What the Pharisees got right

First of all, allow me to thank @PewienBear and @Scutum for the inspiration that lead to this post. At the time of writing, they are probably still duking it out about theology, so go watch them if you have enough popcorn handy.

The Pharisees got something right. They did not get a whole lot right, considering how often and how forcefully Jesus Christ of Nazareth decided to unload on them and their hypocrisy and other sins, but they did get one thing right: Righteousness itself. The law they professed to follow was in fact God's own law at the time.
A few caveats are in order. Yes, they royally sucked at following said law despite publicly preaching it, and most of them completely missed the memo that Jesus of Nazareth is indeed the Christ, leading to the first recorded example of "How Deer Ewe!?!" (Luke 13:11ff). Furthermore, said law was fulfilled by Jesus Christ on the Cross.
That being said, what does this fulfilled law look like? What does God require of us in response to His Perfect Love? I cannot tell you that with certainty. But I can offer a few pointers.
For starters, we have Matthew 5:20. Individual translations vary, but the gist of it is that Jesus tells us we have to be 'more righteous' than the Pharisees were. More righteous means the Pharisees were righteous to some extent. This begs the question: what were they righteous about?
I contend that they were righteous about the law. The law that Jesus came to fulfil, as per Matthew 5:17. Again, we arrive at the question above: what does this law look like?
We are told, in Matthew 22:37-40 that the whole Law rests on two commandments, to love God above all else and our neighbor as ourselves. Personally, I find it extremely fitting that the God who loves us so much that He sent His only begotten Son to die for us asks us to love. I am no hippie by telling you that it is all about love, maaaaaan, because it very much is.
Getting back on topic, what is this love that explains everything? It does not take a sporadic and inconsistent blogger like myself to tell you that it has extremely little to do with what takes up the skin suit of love in pop culture malware. Shout-out to @architectbear for this rhetorical gem, by the way.
This love is painful. We're supposed to take up an entire cross. What Matthew 16:24 mentions is at least a few hundred pounds of wooden beams, considering that it has to hold a whole human several feet off the ground. Worse yet, if you are a bigger specimen, your cross is also bigger, because it has to hold you up. This sucker scales. Take up your cross as opposed to any old cross.
Next up, this love is sacrificial. John 15:13 foretells not only the Passion, it is also sage advice for us. We have to sacrifice first for God and then for others, in order to love Him and them.
Finally, this love is joyful. The trials are to be enjoyed. See James 1:2, Romans 12:12, and 1 Peter 1:8 among many other verses. I do not know how joyful the Pharisees were, but we have to be joyful.

TL;DR : The pharisees got the old law mostly right. The new law is love, which is painful, demands sacrifice, and you will enjoy the ride.

Much love!