That's the question Paul has for the Galatians. Do you want to be free, or do you want to be slaves? He is angry with them because he told them the truth, he spoke the Gospel to them, and God set them free, and he thinks that they want to be slaves again.
Perhaps they do not understand, so he tries to find an analogy. He tells them about the two sons of Abraham, the son of Hagar (Ishmael) and the son of Sarah (Isaac). Ishmael was the child of slavery, and Isaac was the child of freedom, the child of promise. Isaac was given by the promise of God, and so even though the children of Israel lived in slavery for awhile, they were destined to be free, to live by faith rather than by the law.
What does it mean?
Freedom is a loaded word in our culture. We are the "land of the free and the home of the brave." Paul wants the Galatians to be free, free in Christ, which is not "freedom to do anything you want", even though he speaks of "freedom from the demands of the law." Freedom in Christ is freedom from: freedom from fear that we are not acceptable to God; freedom from keeping the law in a slavish way. But it is also freedom to: freedom to love our neighbor, freedom to love God, freedom for love, joy, peace, joy and all of the other fruit of the Spirit.
Someone wants the Galatians to be circumcised. Paul thinks that these "Judaizers" think it would be a feather in their cap to claim the Galatians for their cause. But Paul says, if they do this ritual, they will be enslaved again, they will be obligated to keep the whole law, they will no longer be free in Christ.
Do you want to be free?
That's the question Paul has for the Galatians.
It's not about self-improvement, but it's about death and resurrection, about freedom and new creation every day. God is making us a new creation, an focussing on what we do is just muddying the waters.
Do you want to be free? Free to bear one one another's burdens, and carry your own load? Free to let Christ live in you? Free to love your neighbor, and claim living resources that are not your own, but that belong to the crucified one?
Do you want to be free? That's the question that Paul has for the Galatians. I think Paul, and Jesus, are still asking.