When you digitized a Type layer, you no longer have the option to revert back to your text and change the spelling, the number of words, or spaces between words.

But why do so?

If you apply a filter, of any type (from the filter menu), you have to do that. This is why Type layers are different to images layers. They are similar to Adobe Illustrator vector type layers and are such (fully editable, gradual etc.) until you convert them from vector to normal pixel layer. This is called digitizing (rasterizing). In previous versions of Photoshop this is also referred to as rendering. There is one basic rule: if you want to use a filter or different effects in your text, you need first to digitize.