The 28-year-old, widely regarded as one of the best midfield players in the world, came through the club's youth academy before establishing himself in the first team.
"I don't know if I would be the same player that I am today if I had played somewhere else, I don't know if I would be better or worse," he told Barca Magazine.
"I have been and continue to be in the ideal club to grow as a player. Barcelona are the reason why I am the player that I am today. I have no doubt.
"It's important to believe in a style of play, in a player profile, but it always has to be married to success. We can't forget that without succeeding, the story is different."
Iniesta has made 415 appearances for Barcelona.