If someone wants to see all of the albums in your FOREVER® Account that you have set to Public, Connections or a group then yes they will have to join FOREVER®, and you will need to add them to your Connections.
Once they join FOREVER®, you can then search their name in your “Connections” section and click on “Add Connection” when you locate their account. You can also “Invite” people to FOREVER® and to be part of your Connections. You can also do this within your Connections section, by clicking on “Invite to FOREVER” in the upper left hand corner.
If you just wish to share an album, you can just create a share link for that album and then you can share it via email, Facebook or just sending the link for the album. Since the album would be set as Public, anyone with that link could view it, even if they do not have a FOREVER® account.