Sterling issued a statement via his Instagram account on Sunday, in which he drew contrasts between media coverage of black and white footballers in the UK – a disparity he believes "helps fuel racism and aggressive behaviour".
The post came a day after Sterling was targeted by Chelsea fans during City's 2-0 Premier League defeat at Stamford Bridge.
Chelsea suspended four people from attending their matches pending an investigation, with the club and the Metropolitan Police launching investigations into whether the England international was racially abused by supporters.
Sterling's public stance has won widespread support and, speaking alongside Leroy Sane ahead of his team's Champions League match against Hoffenheim at the Etihad Stadium on Wednesday, Guardiola spoke warmly and passionately of the 24-year-old's human qualities in the midst of a bleak situation.
"Leroy said it perfectly, he is an incredible person. Raheem is an incredible human being," the City manager said.
"It’s tough to understand today what happened years ago, for the whole history for the black people.
"You have to protect how equal we are, all together. It's tough to understand in the 21st century, we are still in that position – not to accept the diversity that helps us to be better.
"That is why sport is amazing. You live with different people. My kids go to school with Indian people, with black people, with people from everywhere.
"We have to defend and we have to protect them [those who are abused]."
Good morning I just want to say , I am not normally the person to talk a lot but when I think I need my point to heard I will speak up. Regarding what was said at the Chelsea game as you can see by my reaction I just had to laugh because I don’t expect no better. For example you have two young players starting out there careers both play for the same team, both have done the right thing. Which is buy a new house for there mothers who have put in a lot of time and love into helping them get where they are, but look how the news papers get there message across for the young black player and then for the young white payer. I think this in unacceptable both innocent have not done a thing wrong but just by the way it has been worded. This young black kid is looked at in a bad light. Which helps fuel racism an aggressive behaviour, so for all the news papers that don’t understand why people are racist in this day and age all i have to say is have a second thought about fair publicity an give all players an equal chance.
The flashpoint in City's weekend match came when Sterling went to collect the ball for a corner and was berated by Chelsea supporters leaning towards the advertising hoardings, including one man who appeared to use a racial slur.
The fan in question, Colin Wing, denied racially abusing Sterling but conceded he was "deeply ashamed by my own behaviour" in an interview with the Daily Mail.
On suffering abuse of the alleged nature, Sterling wrote: "Regarding what was said at the Chelsea game, as you can see by my reaction I just had to laugh because I don't expect no better,"
"Obviously I think it's kind of sad that this happens still," he team-mate Sane said. "We all support Raheem and are on his side."
"He's a strong guy, a good guy and knows how to handle it. He's not getting down about this stupid stuff."
Guardiola ruefully acknowledged problems of racism are not merely restricted to football.
"Unfortunately it is everywhere. That is why you have to fight every day. There [must be] zero tolerance on that issue," he said.
"I appreciate what Chelsea did, if it happened at my club we would do the same.
"We have to fight for the human rights and for everything to make a better society for the future, for everyone.
"Today we are in dangers. Not just in England, everywhere. Absolutely everywhere, all across Europe."
Returning specifically to media criticism of Sterling, who has starred for City with eight goals and six assists in 13 Premier League appearances this season, Guardiola added: I don't know, really, the reason why.
"Hopefully the reason would be a criticism if he plays s*** or plays bad. That would be perfect! Everyone is exposed to that, the managers and the football players.
"But just for the colour of his skin? Right now, that is ridiculous. That is why everybody has to make the effort to protect this situation."