For all the law is fulfilled in one word, even in this: You shall love your neighbor as yourself.
But if you bite and devour one another, beware lest you be consumed by one another!
I say then: Walk in the Spirit, and you shall not fulfill the lust of the flesh."
Galatians 5:13-16 (NKJV)
Knowing what to do is one thing but knowing how to do it is another thing entirely. You can hear about the importance of living a healthy lifestyle of eating right and exercising but exactly how you do that is something else. People can give you advice on the benefits of investing and saving money but where do you start with that and how do you do it effectively? If you only know what to do but you don't know how to do it you are not really going to be able to succeed in what you need to do, we need both the what and the how of things.
Most Christians understand the idea that we are supposed to be kind and patient and walk in love with everyone. But, if you ask believers how to do that you will get a lot of different answers. We are told in Galatians 5 that we need to serve each other through love and that love fulfills that law, but exactly how does that work? How can you walk in love with everyone, including the people that seem to do nothing but annoy you? The good news is that God not only shows us what we need to do but He gives us the guidelines necessary to be able to do what He tells us to do and the help of the Holy Spirit to do it.
Galatians 5 tells us what to do and it also tells us how to do it. We are told that if we only focus on our liberty, our side of things and what benefits us, we will just end up biting and devouring one another. Insisting on our own rights and ways is yielding to our flesh. But, if we follow the direction of the Spirit of God and follow the guidelines that God gives us in His Word then we will serve one another and not fall prey to the lusts of our flesh. If we follow the flesh we will have chaos but if we follow the Spirit we will walk in love and produce the fruit of the Spirit. The choice of what we follow is up to us and will determine if we walk in love or yield to the flesh.