Ignoring requests for Apple ID

For some time the iPhone6 I carry for emergencies has asked
for my apple ID. I always touch "not now" and go about my
business. So far, there hasn't been any repercussion and
the phone works when I need it.

Why is the phone asking, and will something bad happen, like the
phone not working, if I keep hitting "not now"?

Thanks for reading,

bob prohaska