My tree showed that I went back to Adam and Eve. How is this possible that you would have information that far back?
There is no accurate family tree going back to antiquity (i.e. Ancient Rome, Greece and Israel), yet alone to Old Testament times. But people want to be told that they have links to royalty and other famous people, therefore you will find a whole heap of inaccurate information on the internet.
The only family that has been reliably traced to before 0 AD is that of the Chinese philosopher Confucius.
You'll probably find that the family tree connecting you to Biblical figures is mostly accurate, but there'll be several generations where either doubtful assumptions have been made or people have been literally made up in order to fill in a gap.
See: Why You Can't Trace Your Lineage Back to Adam by James Tanner at: https://www.youtube.com/watch?v=BbUbouESw_s
All the lines in FamilySearch that go way back in history are fun to look at. I use them as a hook to send chatty emails out about historic events. I always say the lineage is not proven, but is implied by the research of others. My main goal is to try and make history alive and interesting to family members. As with all things family, I have mixed success in generating interest.
As is often the case, FamilySearch has provided an answer to this question in our Help Center. If you click the Help icon [the circle with the question mark] that appears at the upper right of the FamilySearch page, then click Help Center on the drop-down list, you will be taken to our Help Center. Type: Adam and Eve in the search field and you should generate two great posts about this issue. You may want to take the time to review the comments of renowned research specialists as well as reading the additional reference material on this subject.
I loved the comments by all three of the individuals who have shared additional information.