Why do people have that fear and hate in the first place? It comes from a very primitive place in the human psyche: an in-group vs. out-group instinct that says "people like me are good, people who are not like me are bad". From an evolutionary perspective, it is easy to see how this mentality is adaptive in a context, where people live in small social units that must compete against other units for resources and survival. The more people feel that the survival of their group is somehow threatened, the stronger these tribal instincts become.
In my experience, people can change and recover from hate, but the only way to do this is by appealing to the same in-group vs. out-group instinct that leads to hate in the first place. The key is for that person to feel as if members of the "out-group" are now in their "in-group", Whichwhich shatters the divide that they previously held in their mind. You mentioned in the comments that you and Bob don't have Muslim friends in your circle, which is not surprising at all. If Bob was actually friends with Muslims, and felt that some Muslims are in his in-group because they share many of his interests, values, humor, etc., it would become impossible for him to hate "Muslims" in general, and he would be forced to develop a more nuanced view on what it means to be Muslim.
I have had this experience many times in my life with homophobic people. I grew up in a very homophobic environment, including my immediate family and many friends growing up. Long before they knew I was gay, I used to argue with them about their homophobic views using facts, logic, science, etc. I thought that if I could just come up with the perfect, irrefutable argument, then I could change their mindsI thought that if I could just come up with the perfect, irrefutable argument, then I could change their minds. But it never worked out that way. It seemed like my arguments would only entrench them further in their views, as they would find their own dubious "science" and "facts" to support the idea that gay people are disgusting, unnatural, perverted, immoral, and harmful to society. It wasn't until I returned home as an adult and started saying two simple words, "I'm gay", that the vast majority of people I was close to actually changed their views on homosexuality completely. I have even heard some of these former homophobes standing up for LGBT people when they hear negative comments in their wider social circle, and it is all because when they think of gay people now, they don't think of some scary imaginary weirdos out there in the world threatening their sense of normalcy- instead, they think of ME, a normal person in their in-group who they care about. Thus, the same in-group vs. out-group instincts that made them hateful towards LGBT people in the past have now made them protective towards LGBT people.