Did you notice that anyone can argue for his chosen political candidate based on any facts, depending on how he chooses to interpret those facts? The old saw, "Statistics don't lie, people do." applies. The same goes for religion. She'll make her observations fit her basic beliefs, mostly the ones which she's been taught or which help her cope with life's ambiguities and problems. And if you give them information which contrasts with what they want to believe (cognitive dissonance), they'll ignore some of it, reframe some of it, or struggle with what they thought they believed. Rarely are people so open-minded that they listen and change their views. If you want to lose friends or make people uncomfortable, argue with true believers. It ain't gonna work, folks.
So, how does anyone learn anything new, grow and sometimes switch opinions or broaden their ideas? In brainwashing, it happens by being bombarded with a closed set of ideas which sound logical (or even may be). Watching or listening to the same commentator or teacher over and over could work. With others, it happens a little at a time, when people they respect give them bits of information which they can gradually integrate into their psyche, manipulate and use to revise their knowledge or opinions.
Also, life events drastically change people's minds, especially when unexpected. Caring for an elderly parent, losing or gaining large amounts of money, jobs or professions, relationship transitions teach people from within their inner being and often result in philosophical, political or religious shifts. I know someone who found a distaste for government intervention after working for the government and someone else who found a need for it after major health issues and job loss, for example. I know many people who "found religion" when they cleaned up from drugs or crime and others who left their religion when they became more independent and educated. Mostly, it's not that extreme but more a matter of relaxation of extreme views or compromise.
Anyway, I'm using the political season as one view of human nature. Let's be aware of how others influence what we think.