PaulS, thank you! That makes a lot of sense and it did fix my problem. 
I do have one more question though, because it still isn't working exactly how I would like: should my loop be continuously running from the code I'm using? When I run it, the message will be displayed if pin 6 starts high and will turn off when it goes low, but it will not turn back on when pin 6 goes high unless I restart the program.