There are more than one deity dedicated to keeping people from living indefinitely. In my world I even have a specific divine assassin class whose sole purpose is to identify and end the lives of anyone outliving their normal life spans, even if such people aren't evil in nature. Short of some kind of divine ascension, I as a GM wouldn't even allow a player to gain such an ageless condition beyond what the standard rules allow.
In my published setting of Kaidan (Japanese horror), if you're a 20th level tengu, you can be immortal as long as you stay on the mountain where your shrine exists. As long as you don't leave the confines of your mountain retreat, you cannot die. However, if you leave the premises, you age at 10 times the normal rate. So even when I allow such a circumstance, there are huge negatives for doing so.