The poll of about 15,000 people found around 44% of people believed in the afterlife in 1981, and the same amount believed that in 2008.
The proportion of Brits who believe in Hell rose over the same period, from 26.2% to 28.6%.
Almost a third of the UK believe in all five of the things explored in the study: God, Heaven, Hell, life after death and sin.
It also found older people were less likely to believe in the afterlife than younger people.
More than half of Britons, according to the study, believe in sin.
Ben Clements, who carried out the research, said: "[It] might be partly a reaffirmation of their faith by the religious in an age of increasing secularisation and perceived marginalisation of Christianity in wider society - as belief system and religious institution."
Currently, regular church attendance in the United Kingdom stands at 6% of the population with the average age of the attendee being 51.
This shows a decline in church attendance since 1980, when regular attendance stood at 11% with an average age of 37.
Linda Woodhead, professor in the sociology of religion at Lancaster University, said: "They [the church] should be paying more attention to the third of the population who call themselves Anglican but don't go to church.
"They should recognise that there's a sincere belief among those people.
"The church should be offering more occasional events and services to cater to those groups.
"Where attendances are growing, such as in cathedrals, is where you give people more agency and control."