If a person has an std and for that he/she never engage into sex anymore, without taking medication, probably will he/she die?or get hiv/aids?

Needs information: Here which std you are talking about ? Any std needs to be diagnose and treated adequately. Without sex unlikely to get std, unless blood / genital fluid exchange happen with some unknown reason than accidents.Hiv is also consider one of the std and untreated person can die. Syphilis is one of the monster that untreated leads to someone life miserable.