Why would anyone want to go back into bondage after being free?
People return to bondage because of the human tendency to grovel in legalism and good works, trying to keep commandments rather than resting in Christ's finished work. The Galatians gave up freedom and joy to be wrapped again in law-keeping, prompting Paul's question of how they could desire bondage again.
Les explains that legalism leaves people crawling in the dust, begging that somehow they can make it. He contrasts that with a woman from Pennsylvania who came out of a rigid religious background and was effervescent in the freedom and grace of the message. The Galatians did the opposite: they went back into that stuff, gave up their freedom and joy, and got wrapped up again in legalism and law-keeping. Paul asks how they could desire to be in bondage again. Les says it is hard to understand, yet that describes the human race; today many grovel in legalism and good works, trying to keep the commandments and not realizing that when Christ died, He paid it all.
But now, after that ye have known God, or rather are known of God, how turn ye again to the weak and beggarly elements, whereunto ye desire again to be in bondage?