@chai2,
Now you're being trivial, Chai. You can do better than that.
People often need to give reasons why they want to do good things, like raise money for a charity, or support a college, or fund a new hospital wing, or any of a thousand other things that will cause people to ask them why they're doing that.
You think reporters weren't camped out at Bill Gates' office demanding answers when he announced he was leaving Microsoft to work full-time on his foundation? I have no idea if his reasons were influenced by religious beliefs, but that is beside the point. What I AM sure about is that he had to answer "why" to at least his staff, his board of directors, his friends, and his family.
When I decide I want to donate money or time to a particular cause, you bet I have to justify that to Hubby. Because it affects him, too.