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.
An ankle injury to Zlatan Ibrahimovic saw the Swedish striker drop out of the squad on Saturday and Henry make only his 13th start of the season before being substituted near the end.
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."
