"Who has bewitched you," Paul pointedly asked the Christian church in Galatia. The tone of the letter is familiar to those who read through the New Testament regularly. The classic Pauline browbeating.
"Did you receive the Spirit by works of the law or by hearing with faith?" He continues. "Are you so foolish? Having begun by the Spirit, are you now being perfected by the flesh?"
These are types of lectures that I'd rather quietly observe unnoticed from the corner. But I've always found it interesting that he starts the letter saying all this stuff against chasing after righteousness through The Law, but then finished off the letter by saying that when we carry each other's burdens, we fulfill "the law of Christ".
It would appear that though the fruits of the spirit that Paul mentions in chapter 5 makes the law of the Old Testament unnecessary, it seems that there is still some kind of law in affect for Christians. One that we are expected to obey and follow.
What is the Law of Christ?
In Gal 5:14, Paul says, "The entire law is fulfilled in a single decree: 'Love your neighbor as yourself.'" And James, the brother of Christ, whose emphasis on works is often contrasted with Paul's focus on faith, agrees with Paul when he writes, "If you really fulfill the royal law according to the Scripture, “You shall love your neighbor as yourself,” you are doing well." (Jam 2:8)
James even calls this the "royal law".
Paul contrasted law with grace because the primary characteristic of the Mosaic Law was its legal character whereas the primary characteristic of the law of Christ is its gracious character. He did not mean that there is no law under grace any more than he meant that there was no grace under the Mosaic Law. - Dr. Constable’s Notes
But as we mentioned in Why God Punishes Us When We Refuse to Forgive, there's a little more to "love your neighbor as yourself" than is initially apparent. Critics of the so called "Golden Rule" have pointed out that you probably wouldn't want a masochist to do unto you that which they would want done unto them. And when the law is worded as, "Love your neighbor as yourself," the word "love" doesn't seem well defined. And what if I don't love myself the right way? Then I can't love others the right way either.
We humans need to know what it really means to "love" before we can love ourselves or, especially, love others. And how do we go about learning how to love? We learn from the God of Love Himself. That kind of knowledge comes from the first and greatest command in the Old Testament, "You shall love the Lord your God with all your heart and with all your soul and with all your mind. This is the great and first commandment." (Matt 22:37-38; see also Deu 6:5)
By loving God and growing in our relationship with God we then can learn what it means to love ourselves. And when we know how to love ourselves we have become equipped to love others.
And this commandment we have from him: whoever loves God must also love his brother. - 1Jo 4:21
So, is that the Law of Christ? To love God and then love ourselves and others? Essentially, yes. But Jesus didn't stop there. He condensed those two laws into one before His betrayal and death. In John 13:34, Jesus said, "A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another."
You see, it's no longer necessary to separate "learn how to love by loving God" and "love others". Now, all we need to do is see how Jesus loved and do the same. By loving as Jesus loved, we have learned directly from God and, therefore, are equipped to love our neighbors. Through Jesus, the two sides of the Old Testament Law have become united in One Royal Law. That is the Law of Christ: to love as He loved. That is the newest commandment in the Bible and it's now the greatest. To Love like Christ.
"This is my commandment, That you love one another, as I have loved you." - Jesus Christ, (Jhn 15:12)