What is a truth about human nature that most people refuse to accept?

What are some signs that it's time to agree to disagree when talking about spiritual beliefs, and how do you do it respectfully?
Why is the ability to be fully present with someone becoming such a rare and valuable skill today?
Even if God existed why should we worship him when he created all the pain and suffering in the world? How could any religious person actually believe God is "all loving and all good" and "all mighty" at the same time?