You fail to see Galatians in the light of the arguments in Romans by Paul on Grace, Law, & Sin.
Start by reading Romans 6
Romans 7:7
7 What shall we say then? Is the law sin? Absolutely not! Certainly,
I would not have known sin except through the law. For indeed I would not have known what it means to desire something belonging to someone else if the law had not said, “Do not covet.”
Romans 13:8-10
8 Owe no one anything, except to love one another, for the one who loves his neighbor has fulfilled the law.
9 For the commandments, “Do not commit adultery, do not murder, do not steal, do not covet,” (and if there is any other commandment)
are summed up in this, “Love your neighbor as yourself.” 10 Love does no wrong to a neighbor. Therefore love is the fulfillment of the law.
(Sorry only have King James Version in my computer)
What is Paul saying? That without the law, he doesn't know coveting is a sin. How could one know what is sin without the 10 commandments? This is exactly what Paul is saying. Which is why Galatians 5:22 only can be viewed accurately and what does Paul means "Against such things there no law".
What is Jesus commandment? Love one another... In other words Love your neighbor as yourself. How do you do that? It's right there in Romans 13:9.
Though we are not under the law but we are required to know the law in order to know what is sin. When you sin it displeases God and when you don't? It pleases Him because you obey Him.
Furthermore, I did not say nor imply the 10 commandments produces sanctification but the Holy Spirit.
No point argue with him. He will turn and twist the facts. I call it Pick Durian.