is there a way to have the members plugin be the only login? Instead of having another signup for th

I have a site and on it i have the membership plugin, and a forum plugin. When someone registers on the site i want them to have access to everything on the site including the forum. But when they register on the site they have to put info in and then have access to the site, but then they have to be a member in order to access the protected content, and then another register to post in the forum. Is there a way to just have one login for all of that?
Thanks
Brian