So far, so good...
the absolute belief that the other will not be saved in his belief,
No, that's not why I engage in apologetics with non-Catholics.
I make no decision about their eternal destination. That's for the Almighty to decide. Most of my discussions with them involve me explaining Catholic doctrine after it has been distorted or attacked. It's not about the person who's engaging me in dispute. They already know the Catholic point of view in most cases and have rejected it.
It's about third parties. It's simply about ensuring that any lurkers of good will understand true Catholic teaching.
.... therefore, they are trying to save their eternal life. That conviction is a sign of true love......
That's a silly assumption. Nothing more.
When a Muslim places his scimitar to your throat and screams "convert or die", you think he's doing it out of true love?? You think he truly cares about your eternal salvation? After all, there's nobody more "convicted" than a Muslim, is there?
The real reason is hate fueled by an infernal pride. It's the belief that your faith is evil and that those who follow it and profess it are evil too. Therefore, your faith must be destroyed and if you attempt to defend it, then you must be destroyed too, because, (the assumption goes) that's what God wants. That's where the pride comes in. I speak for God.
There's a word for that. It's called fanaticism.
It's the same with some non-Muslims on these boards.
The aim is not to save. It's to destroy.
So, you are saying you are only writing to correct the distortions put out there about the Catholic faith.That you are not making any effort to convert them,since those writing have no ears, they will not listen anyways. That your efforts are for a third party reading the posts.
But what is the point of defending or correcting, if it's not to save their souls from eternal perdition? Why not just leave them alone, and go and live your life?