Someone help me Exegete

So I have to teach Galatians 3 & 4 on Sunday.
I don't like this Paul.
Granted, I don't like very much Paul, but this Paul isn't a very good scholar, to boot. He's got proof-texts all over the pages. And he's clearly telling the story his own way to make his point.

I have NO IDEA what to tell my class of 30+ senior addults in a Baptist church in Western Kentucky!!

Any ideas? Can someone help me come to terms with these difficult passages? I need to reconcile my biases and theirs and come to a place where we can at least discuss the difficulties inherent in the text.