SIM card removed? How do I read my messages?

I was out of the country for a month and I removed my SIM card from my iPhone 4s. None of my messages came in when I reinserted the SIM card. Is there any way I can find the messages sent to me during that month?

No, the device was not on the network for that month. It had to be in the network with the SIM card for you to get those messages. Now that is in the past you are out of luck.