A parenthetical in this particular situation would be totally stylistic. Personally, I think your sentence would flow best without commas and instead with “and”. Is allowing religious freedom a valuable and necessary cultural achievement? Is “indeed” for “in fact” correct? “, Inserting parenthetical kind of implies the insertion of a separate piece of information which only affirms the information you’re presenting. “In fact” creates a clear segment of thought. What is religious freedom, is it a cultural achievement? Can you include a comma between “needless something” and “cultural”?