Q. The small group at my church is going through the Genesis study guide right now. There seems to be a wide variety of opinions in the group about whether these stories actually happened or not. Are the stories of Genesis historically true, or are they just stories? No one in our group seems to know the answer. If they’re not true, then why are they in the Bible?

Faithful followers of Jesus who are equally committed to the divine inspiration and entire trustworthiness of the Bible have long given different answers to the question you’re asking about Genesis.
Some believe in what is known as the scientific and historical inerrancy of the Bible, meaning that all the events happened exactly as they are described. But even this view makes some allowances for the observational perspective from which the stories are told, for example, the apparent understanding that the sun revolves around the earth.
Others believe in the doctrinal and practical inerrancy of the Bible, meaning that through the stories it relates, the Bible primarily teaches us what we should believe about God and how we should live in order to please God. This view acknowledges that the stories in Genesis have been passed down faithfully over the centuries through the community of believers. But this view sees those stories as potentially more affected by the limits of the human perspective than the other view does.
Either way, because the Bible is the word of God mediated through human authors, these stories have a legitimate place in the Bible, whether or not we can verify every detail historically and scientifically.
It’s easy for any discussion of Genesis to be completely taken over by the debate between these two views. That’s why the study guide you’re using invites group members, at a couple of key places, simply to share their views (about the age of the earth, session 2, and about Adam and Eve, session 3) and then hold those views confidently and humbly and join the others for a profitable discussion of the Genesis stories on their own terms. I trust you’ve been able to do that in your group.
One reviewer of the Genesis study guide on amazon.com has appreciated this approach, writing that the guide “wisely decides not to discuss the various creation/origins alternatives, as doing this can short-circuit getting to the other things in Genesis.”