How to Quickly Upgrade Materia
As noted above, the Materia can be upgraded by gaining AP in battle. Some Materia like Ice Materia only need 300 AP to reach the second level and even more to reach the third and final level. One in particular that has a really high requirement is that of Material Rebirth, as it requires 5000 AP just to reach the second and final level to gain the Arise spell.
Unless you're really creaking as you play, this is one Materia in particular that you'll likely need a little help leveling up and we've got some tips on what you can do.
You will have to wait quite a while in the game when you reach chapter 14. In this chapter you will come across a mysterious Materia pedometer right on the ground as you exit the area around Aerith's house after the emotional scene with Tifa. You shouldn't be able to miss this one Materia, as the purple orb detaches when you approach to leave the area. Once you get this Materia, you'll want to equip it immediately.
This Pedometer Materia works differently from any other Materia, as it is the one that levels up by walking. From there you have to walk 5 steps, which will turn the Materia into an incredibly useful AP Up Materia. From there, you need to equip it on a character with a Materia spot connected and place the specific Materia you want to get double the AP in the other spot connected with it.
AP Up is not the only way to improve your Materia faster. In fact, there is another way that can be stacked with Double AP to actually give you six times the AP. The only downside is that you have to wait until you beat the game. Once you beat Final Fantasy VII Remake and have access to the chapter selection, you can come back into the game at any time and automatically win three times. AP for each battle. Pairing with the AP Up will get you to 5000 AP you need for the Revival Materia and many more in no time.