You look for information from the original source, not opinions. You take that information and come to your own opinion. You validate your opinion with an open mind and curiosity - look out for people who can challenge their views. You introspect and change your mind. You also say that some information is beyond your comprehension and “too hard to understand”. “I never allow myself to have an opinion on anything that…
To add to this: if you grow into this approach, it's almost impossible to become a "radical" believer in anything; usually any serious discourse has very solid points on both sides, which are formulated by very smart people. It's quite hard to live with it, actually, humans are not built for seeing nuance everywhere.
While there are usually solid points on both sides of an argument, you should take one side on many (most?) issues.