The 22-year-old now has 25 Premier League goals in just 19 appearances and 31 in total just halfway through his first season with the English champions.
"The numbers are incredible," said Guardiola. "He lives 24 hours for his profession, job, passion, love.
"He’s not stressed much when it’s going well or going bad. He is stable."
Haaland's remarkable scoring rate has slowed slightly in recent weeks and with City trailing Arsenal in the title race, questions had been asked over whether Guardiola's men function better as a team without a natural striker.
City have won the title for the past two years while largely playing without a recognised number nine.
"When he played and scored, I don’t know many goals, he is the solution and everything of the team and when he does not score, he is the problem in our team," added Guardiola.
"We know his quality. We know each other. He is not a player to be dropped. We can’t play the false nine with him. You have to adapt some movements with him and we are doing quite well."
A comfortable win was just what Guardiola was looking for after he called out a lack of hunger and desire from his squad to retain the title after coming from behind to beat Tottenham 4-2 on Thursday.
"We talk a little bit these days about what we think we miss," said Guardiola. "It’s just one game. We will see in the future.
"Our football was really, really good. Today we improved. That was just today. We will see what happens in the next games."
