Outward Rituals cannot destroy Ignorance

"Outward rituals cannot destroy ignorance -
because they are not mutually contradictory."

"Realized knowledge alone destroys ignorance... "

"Knowledge cannot spring up by any other means than inquiry."
                                     (Excerpts from ShatPadi (Hundred verses) by Adi Shankaracharya)

There are two parts to the above statement.

First - Ignorance can not destroy ignorance.
Ignorance cannot be eradicated by abandoning one misconception and adopting another.
Replacing one ignorance with another type of ignorance does not mean we have achieved Gyana - the true knowledge - the knowledge of Self or enlightenment.

Achieving Gyana means eliminating all ignorance, delusions, misconceptions, and blind faith.

Second - 

The only way to achieve Gyana is through inquiry - by questioning everything till completely satisfied. 
It is natural for questions to arise in the mind until there is a complete understanding.
Therefore, if there are any doubts or questions, it is better to resolve them by asking a Gyani - the learned ones. 

Gyana means the realization of truth.

Lord Buddha said: "Do not believe just because I am saying it.

Bhagavad Geeta says: "Pariprashanen Sevayaa" (BG 4-34)
'By the means of genuine and respectful inquiry' - by questioning respectfully.

I have heard Baba Avtar Singh ji emphatically saying:
Do not believe something simply because I am saying it.
Listen to me carefully - analyze it and compare it with the holy books and Shastras. If you are satisfied - then accept it - and adopt it in your life.
There is no place for ignorance, delusion, or blind faith in the mind of a Gyani.
                                              " Rajan Sachdeva "