You could actually use either, but you'd need different punctuation. Further, for clarity, I'd stick a colon after the first "is."
The first point I feel the need to address is: why it is important to ask such a question.
*The first point I feel the need to address is: why is it important to ask such a question?"
Here is where "forgot the grammar terms as I internalized them" is a handicap for me. Sorry. Basically, the first version ("why it is") translates to "I want to explain why asking this question is important." This is explaining, not a question. But the second version ("why is it") turns the statement into a question because of that word-order, and therefore requires a question mark.
Either one would be acceptable, though the nuances are slightly different, and the first one feels more formal. (Because it's not a question, and therefore is more "firm.")