I would think being unequally yoked means believing in ways that do not align, having different viewpoints on life, etc. I think two people need to have more in common than just a belief in GOD. Being an autistic person most people have no idea how hard it is to find a like-minded individual.
aren't there lots of autistic support groups now
You can find them online?
I've found that its very hard to find a like-minded individual in all areas, I may have things in common with someone but be totally different in other areas, or they may be much older or younger, or even if the same age as me as in my school peer group, or class, everyone was different, and as you go through life you may change your viewpoint/mind on certain things. Some people are very fixed in their thinking, others are more fluid.
Some people are very opinionated, and others don't have any opinion at all (or not drawn into having one) I'm not sure what can be more annoying, and its very unlikely you'll ever find someone with the exact same views/background as yourself, even in your own family.
Christians don't just have a belief in God, they believe in his son Jesus, because Jews believe in God but not Jesus, and muslims believe God is Allah, and Hindus believe in God (or many Gods) but their concept of God is quite different from the God we know.
However I have learned that some Christians while believing in Jesus then come to blows over doctrines, or tongues, or baptism, church politics or a thousand other things that cause great dissent in Christian circles. Its just neverending...you find one thing in common then a bunch of other things that are different!
with marriages I think it ends up the most couples have in common are their children lol.