Graeme Scott, 44 and from Irchester in Northamptonshire, was speaking in the run-up to a church service marking a year since the atrocity which saw 30 Britons murdered.
Mr Scott (below, far left) was in Sousse with his parents and cousin when gunman Seifeddine Rezgui went on a rampage and forced him to hide for their lives in a cellar with around 20 others.
Seifeddine Rezgui was eventually shot dead by police. Islamic State claimed responsibility for the murderer's actions.
"It's a strange feeling... he will never be able to apologise for what he's done," Mr Scott said.
"To a degree it's sad that nobody has been accountable.
"It's something that I will have to live with for the rest of my life, but being a Christian the forgiveness will be there."
Commenting on seeing the dead bodies and blood, Graeme Scott said: "It was a sight that will live with us for a long time.
"It's very hard still to this day."
Sousse survivors have kept in touch and will meet on June 26th for a church service and lunch remembering those who died - a year on from the massacre itself.
