I was doing some modeling in Blender. And if you look closely in object mode, you can see some edges that overlap in the second column from the right.

I went to delete them in edit mode, but they disappear when I go into edit mode.

My first thought was that I needed to apply a modifier, but as you can see in the first image, there are no modifiers. Does anyone have any ideas what is causing this and how to fix it?

Interesting.  One thing that could cause this in some cases is if you have some geometry "hidden" in edit mode.  In edit mode, unhide all geometry.  When you are in edit mode, press ALT+H

That was it. thanks. I must have hidden it accidentally. Thanks so much

Glad to help.  That can certainly cause confusion in cases where you may have accidentally hidden something by pressing H.  Unfortunately, unlike in object mode, I don't believe there are any visual indicators that one has hidden geometry in edit mode unless you try to unhide all or notice that parts of the geometry are missing.  It happens to the best of us.