It really depends on what these 'things' are... I think we all withhold certain information about our personal life or deeply held beliefs from our family. It's just not worth souring this relationship with a political or religious debate, for instance.
I've made the assumption here that these things he feels strongly about are unrelated to the core issue, and this is where I'm coming from. I may be wrong. Ignoring a problem is never something I'd advocate.
> You should be able to discuss these things with mutual respect even if you don't agree with the other person's opinion.
That's a nice thought. But reality falls short of these ideals.