Need help with something, please

Hey my brother needs to get into the Besaid temple but the warrior monks won't let him in. He needs to get in the cloyster of trials and get the destruction sphere and get the chest there. It's been awhile since I played the game so I don't really remember what's next in the story...

If I'm not mistaken, you have to fight Sin while on the airship soon, right? And I forget as to whether you can still go do other things in a non-linear fashion after that or do you immediately go inside Sin after that battle?

Heh, I just ran into the problem yesterday, but I solved it. They won't let you in till you've went and fought Sin. After you've fought Sin, go back and they won't stop you from going in anymore.

Thanks a bunch! :D

Yeah, I just wasn't sure if by fighting Sin you reached that "point of no return" in the game...but I guess not! yay