Simplify the following text for a Grade 9 native English-speaking person.
Original: Celtic Reconstructionists are not pan-Celtic in practice , but rather immerse themselves in a particular Celtic culture , such as Gaelic , Welsh or Gaulish .
Simplified: Celtic Reconstructionists base their religion on what we know of the Ancient Celtic people 's religion , and also on Celtic folklore . They focus on a particular Celtic culture , such as the Gaelic Welsh or Gaulish .