Is there a way to turn crystallized honey back into liquid honey?

Yes, you can. If you heat it in the microwave (make sure not to put thin plastic in there, as the plastic will melt), or add hot water (steaming, not boiling) to it, it will turn back into liquid. For the microwave, make sure you have the lid of the honey jar off, and check it every 10-15 seconds in the microwave until it turns back to liquid. Make sure to not put it in there for too long; it will boil over if you heat it too much!