Christ warned us that a house divided cannot stand.
St. Paul's writings continually urge Christians to unify in heart and mind and spirit. We are to be one body in Christ. So unity is a very important. One might easily read it as a command of God.
Therefore, for the sake of unity in Christ, we really need to try and find a way to unite and when Protestants misunderstand Catholic beliefs, there can be fearfulness, defensiveness and undo skepticism.
While there are many things Catholics and Protestants DO disagree on, many things are simply misunderstood.
I like to put it this way. So much of the differences between our faiths are similar to the differences between our current GPS system and a navigational sextant. If one needed to get to Brooklyn Harbor in New York, one could get there using either method, but you certainly couldn't assume the language and mathematics are the same. They are very different.
Catholicism uses the language of the early Christians, it takes the route of Hebrew (Aramaic) and Greek to Latin. Its worldview is from a different millennia and language and culture. Protestant thoughts are based in the 17th-century European Reformation and are intermixed with Enlightenment philosophy. European language and culture is very different from first-century Aramaic and Latin, therefore attempting to see ancient culture through today's lenses simply doesn't work.
You cannot understand Catholicism easily. It's not a matter of googling a question and then assuming you understand anymore than trying to figure out how to get from New York City from Miami using a sextant system from your car. You have to first get the translation...
And to complicate things further, the definition of common Christian words mean very different things to Catholics than they do to Protestants.
When I was a Protestant and a Catholic would use the word "grace" I assumed I understood what they were saying. I didn't. And I assure you, if you are a Protestant and think you understand Catholicism because we share a spiritual vocabulary and think you know what Catholics mean by the word "grace" you don't. Trust me on this one, you don't.
Another example of what I mean is the Magic Eye pictures. Look at the one at the top. Those who have no idea what it is, just assume it is a strange mosaic repeating images of colorful dancer and buildings. But once you learn that it is not, there is a hidden image beneath the surface of the images, that the point of the repeating images is not for the superficial but for the deeper image, then you begin to look more intensely.
After a while you can learn to see the images the creator meant for all to see. It just isn't easy. However, Catholicism isn't hidden in the sense that it is a gnostic secret that only a few have. It is for everyone. The difference for us today as 21st-century Americans understanding Catholicism is not that it is so mysterious and hard. It is just ancient. That alone makes it a difficult transition for us.
(By the way, the picture is of Boston's Hatch Shell. I'm usually pretty good at these magic eye pictures, but this one just isn't working for me.)
One more example:
This is the Lord's Prayer in Old English.
This is a language we should all easily comprehend. It's English.... Yet, just as Shakespeare is difficult to follow and it is only a few centuries ago, a more ancient English is almost impossible for us.
So when we try to understand Catholicism, which is two millennia old, in a different language and in a different culture, we should assume we will have to do some studying first before we can be assured we understand.
Please, for God's sake, understand that Catholicism cannot be understood in Protestant language nor in short sound bites anymore than one can traverse land today via a sextant or see the picture in the Magic eye or understand Old English on the first hearing. Catholicism is ancient. Be patient. Listen with an open heart and you will discover that you can more easily see ways to unite with them. Not for our sakes, but so the world will know that Jesus is God.
"I do not ask on behalf of these alone, but for those also who believe in Me through their word; that they may all be one; even as You, Father, are in Me and I in You, that they also may be in Us, so that the world may believe that You sent Me. "The glory which You have given Me I have given to them, that they may be one, just as We are one;… John 17: 20-22.