I am playing Oblivion on the PS3. Anyways this is what happened. I enter the portal that leads you to the demon world at the beginning of the world. I DID NOT talk to Martin before I went in. After I got the stone inside the tall towers and then it returned me back to the human world I followed up with the attack alongside with Martin against the demons at Kvatch. After that was done I found the dead priest's ring and gave it to Martin. Martin gave me the Kvatch Cuirass and that was basically it. Now I am trying to do the quest "Find the Heir". But when I talk to Martin he just goes on talking about rebuilding Kvatch again and that its. Is my game screwed now? I believe "Find the Heir" is a main quest and I need it to proceed. What should I do?

Are you sure you're talking about the right guy?

http://www.uesp.net/wiki/Oblivion:Savlian_Matius and http://www.uesp.net/wiki/Oblivion:Brother_Martin are two entirely different NPCs. Martin does not do any of the things that you're describing. Savlian Matius does all of those things.

Oops sorry I had my names wrong. Yes it is the guy you are talking about. Even the map marker leads me to him, standing inside a castle without any body armor on.

The reason its leading you to him might be that you still have "Retaking Kvatch" or whatever the quest is named as your active quest still. If this is the case just make the other quest your active quest

Yeah, you've got the wrong guy. You want Martin, he was a priest that was inside the chapel with the other survivors, a Redguard woman should have lead him outside, and by this point he's probably outside Kvatch at the camp where the other survivors are.

As said above, the quest marker leads you to Savlian Matius because you have the wrong quest active.

Ah thank you so much for lending a hand! I came to the camp you talked about and I found him. Now I can proceed on with the story. However, I don't get how this has happened. At the time, the quest Retaking Kvatch or something wasn't active and I have set "Find the Heir" as my active. Either way the game is good now all thanks to you guys!