iPhone 5s missing and off-line how do I retrieve messages?

Voicemail is handled by the carrier. I would contact Verizon to see what the options are for listening to your voicemail from another phone.

Dial your own cell phone number from any phone. When you hear your recording, interrupt it by pressing the pound sign. You will be asked for your passcode. If you don't know the passcode, Verizon can reset it over the phone or you should be able to do it yourself by logging into your Verizon account on a computer. You can also arrange to have your number forwarded to another phone either by customer service or online.