Sour beers are always a way to make people talk. If you don't like them you'll probably let everyone near you hear it. If you like them you probabaly like them so much that you'll tell everyone. Either way they make you talk a lot.
Sour beers are often said to be an acquired taste, but how many and which do you have to taste to learn to love the power of the sour?
Maybe sour beers like the Mikkeller Baghaven beers in the picture are not the place to start. A fruited sour beer of some kind - a sugary fruited kriek or a fruit loaded berliner weisse could be the answer.
Do you like pickled foods like what we eat in Denmark you might have a head start in to the field of sour beers. Some people just don't like the vinegar flavors and by that it can be hard to fall in love with the Belgian style sour beers since some of them are loaded with these flavors.
Sour beers may sound like a beer style you have to like. That's not the case at all. It's just that I (and many other beer lovers) like them a lot and values their complexity and multiple flavor character traits. Sour beers adds a new layer of joy to beer. In some ways they are venturing into wine country with their acidity and often with a lot of barrel notes to the flavor.
If you have some wine loving friends they might be in to sour beers. At least it's worth to let them try it once or twice. A place to start could be the always tasty Alexander by Rodenbach. It's a fruited Flemish red that's not over the top sour and the fruit might help someone to like it.
If you try to teach someone the power of the sour beers, just remember that it's completely okay not to like them and it's equally okay to say it out loud.