How can I get my 15 month old cat to be more friendly?

We have had him since he was a kitten. He is always in hunt and attack mode. Likes being in the same room with people, but does not like to be touched or held. Will not sit or snuggle with anyone. He allows me to hold him for a few minutes every day, but I have been working on this by giving him a treat or before I feed him. Does anyone have any other suggestions?