In Final Fantasy VII, most characters have Level 4 Limit Breaks, and that includes Aerith Gainsborough. However, it can be difficult to find and teach her Great Gospel before she leaves the party. If you're looking to do that, expect to have to go out of your way and grind a bit first!
Great Gospel Guide
While you can obtain the Great Gospel item at any point in the game, you'll need to teach Aerith the ability before entering the Temple of the Ancients. If you don't, it'll be too late.To get the Great Gospel item that early, though, you'll need to go out of your way to grab it.
First, head back to Nibelheim, and take the Buggy back to Costa Del Sol (drive directly into the town). Pay the sailor to return to Junon, and the Buggy will be waiting for you outside the town.
Drive the Buggy east, across a river, and look for a cave in the mountains to find a sleeping man. Talk to the sleeping man continuously in order to learn how many battles you've fought so far.
With the knowledge in hand, you'll now need to fight battles until the last two digits of battles fought are the same, but are also odd number. Examples of these numbers are 133, 277, 199, 55, and so on.
Once you've fought enough battles, return to the sleeping man and talk to him again. He'll wake up and give you some Mythril.
With the Mythril in hand, head to the Golden Saucer area. Instead of actually going into the theme park, though, head to the southeast to find a house. Talk to the man and he'll take the Mythril and offers you either a big chest, or a small chest. The Great Gospel item is in the small treasure chest, and now you'll be able to grind Aerith up to learn it.
