I was wondering if I could write an equation, symbolically, but only as part of a text in Mathematica. So I don't want Mathematica to consider anything inside that equation as a variable, nor equate or perform any mathematics on it. Is that possible?
You can open a text cell using Alt7, and type some text. When you need math, open a subcell using Ctrl9. Single letter variables will be formatted in italics in the subcell, as is usual. Use the usual shortcuts (e.g. Ctrl6 for superscript) to enter math. Use CtrlSpace to get out of the subcell (or the arrow keys).
On a Mac, use ⌘ in place of Alt.