>>729558
There are three forms of baptism.
Baptism by water - which is the normal version.
Baptism by blood, which is via martyrdom prior to getting the opportunity to be baptised.
Baptism by desire, which is what >>729566 suggests with the thief on the cross. Which is where you would sincerely want to be baptised, but can't before you die. Both these latter two forms are irregular and probably wouldn't apply to you.
The fate of the virtuous men who never had the opportunity to hear about Christianity and thus be baptised is disputed. Some say they have a chance at salvation, others deny that possibility, still others suggest a form of Limbo (see Dante for a literary example of that).
The fate of those who deliberately decide not to get baptised after hearing the word of Christianity seems to be less amenable to dispute. Simply put, if you wish for salvation, being baptised is your best bet.