Dont worry, this is a completely natural process that all honey goes through.    There is nothing wrong with the honey and it can still be eaten, however, if you would prefer your honey clear then you just need to heat the honey up to clear the crystals back down again.   You can do this by standing the jar of honey in a saucepan of Hot water until it has cleared.    This can take a few hours depending on how crystalised the honey has become.    You can also microwave the honey but make sure you remove the metal lid and stir regularly during the process to make sure it clears down evenly.