The former Arsenal player netted only his third goal of the campaign in the 4-0 home victory at the Nou Camp with a free-kick in the 29th minute.
"We hope the goal lifts his spirits. His team-mates and myself expect a lot from him," Guardiola told reporters.
"I have never lost confidence in him because we desperately need him but we need him playing to a slightly higher standard than that which he has been doing. I demand more from him."
Henry cut a forlorn figure on the bench in Barca's previous three matches.
Barca sports director Txiki Begiristain backed Guardiola's assessment of the 32-year-old.
"It's always good to score a goal. We hope it lifts his spirits, his confidence and his desire to help out," Begiristain told Canal Plus television.
"He is a great player who last year made a huge effort for the team playing on the wing and scored 26 goals. For this we will always be grateful."
