The 29-year-old travelled to Catalonia on Monday to complete his move and has agreed a two-year contract with Barcelona.
Jesus was at Camp Nou on Monday night to watch his new team-mates beat Rayo Vallecano 5-2, a result that kept Barcelona's perfect start to the Liga season intact after three consecutive victories.
He is due to be officially presented on Tuesday as Barcelona's sixth major signing of the summer.
Flick said he was surprised that Arsenal were willing to allow Jesus to leave so late in the transfer window but made it clear that he was delighted to have the Brazilian in his squad.
"I was a little surprised we had the opportunity to get him," Flick told reporters.
"I really love him, I like his style to play football, it fits with our style. I think he can help us a lot in the games."
Barcelona have been busy strengthening their squad during the summer, with sporting director Deco already bringing in Anthony Gordon, Karim Adeyemi, Rodri, Joao Cancelo and Dominik Livakovic.
Flick was quick to praise Deco for completing another important piece of business.
"For us, he can be an important player, so thanks to Deco because again he made an excellent job," he said.
Barcelona had also explored the possibility of signing Julian Alvarez to strengthen their attack, but Atletico Madrid refused to negotiate a deal with their domestic rivals.
Jesus now joins an already strong Barcelona forward line and will hope to quickly make an impact under Flick.
Barcelona return to action on Sunday when they face Valencia at the Mestalla.
