About the Almighty or Maha shakthi:
The above is just one of the innumerable attributes of Allah, the One and the Only One. When we say All Mighty, we have to follow it up with the One and the Only. Allah means the One and the Only for all needs of mankind. We are not to associate anything on the earth and in the skies or anyone to the One and the Only, which if we do, we do not find our prayers answered by Allah, unless His Name, the One and the Only is invoked.
So we are not to say: All Mighty as Allah -
But we say: The Almighty, Allah(the One and the Only).
Like Almighty, in all our needs is His Name, or His Attribute. Examples being: The Provider, Allah(the One and the Only); The Hearer, Allah; The Healer, Allah; The Forgiver, Allah; The Seer, Allah; The Knower, Allah; The Merciful, Allah; The Wise, Allah; The Peace Giver, Allah and so on. If we do not follow up our call upon God, the One and the Only now in the beginning of any of your adversities, towards the end stages of afflictions we will be forced to call upon God as the only One to save us. And Quran is not religious book for the 'muslims' but to the mankind in total. And Quran abhors religious groups but gives guidance for the formidable life of mankind in both the worlds.
And as to your other question why I refer to Quran, I should submit, "I can say from only what I know of and what I follow; and I cannot say anything from the hearsay and what I myself do not do." If I had spoken to you from any other thing that which is not my life, you would not have found the solace at heart you gained in the meeting you attended; and you would not have gotten the relief from your ill-at-ease, the chronic fever.
And Quran is guidance to Allah, the Master of the world below and the worlds above.