Allah (SwT) has said,
“Say: Allah is the Creator of all things, and He is the One, the Supreme” (Qur’an, 13:16).
Linguistically, al-Qahhar is derived from qahr, conquest, subduing, vanquishing, and winning a victory. It means the overtaking of something or someone with the intention to humiliate him. One who takes another by way of qahr is one who takes him against his will. Al-Qahhar is a superlative of al-Qahir, the Victor or Subduer. Allah (SwT), indeed, is the One Who, by His Might, has subdued everything He created to His Authority and Power, using His creatures as He pleases, whether they like it or not. Al-Qahir is the One Who has the upper hand over all creation;
“... and Allah is the Master of His affair” (Qur’an, 12:21).
Al-Qahhar is the One whose vengeance nobody can withstand. He humiliates oppressors, splits the spine of kings and emperors. He is the One besides Whose Might all creation is powerless, without Whose Power all beings are helpless. If we submit to Him, He will meet our needs, but if we do not, He will make us suffer as we try to achieve our objectives. He is the One Who splits the spine of the tyrants and oppressors from among His foes, subduing them by taking their lives away, and by humiliating them, while there is nothing in existence that can escape His Might and Power: everyone and everything is helpless in His grip.
Al-Qahhar effects His will with regard to His creatures, whether they like it or not, whether they are willing or unwilling. He has subdued the souls of the worshippers by instilling in their hearts the fear of His retribution, and the hearts of those who are endowed with knowledge with the Might of nearness to Him, and the souls of those who love Him by unveiling the truth about Him to them.
He has subdued all beings by death, so none is safe from Him, not even an angel who enjoys a special status with Him, nor a prophet, nor a messenger. Allah (SwT) will make even the angel of death, Israel, taste of death; so, when his soul is taken out, the angel of death will say,
“By Your Honor do I swear that had I known the taste of death to be like this, I would never have taken away anyone’s soul at all!” It is to such a meaning that the word qahr, on the taking of the souls of all beings, conveys as implied in the verse saying,”To whom does the kingdom belong this day? To Allah, the One Who subdues all” (Qur’an, 40:16).
If one who believes in Allah (SwT) desires to personify within him the meanings embedded in this Attribute, he has to subdue his own self, his nafs, and control his evil desires, by not plotting in cooperation with Satan, and by returning to Allah (SwT), submitting to His will in all matters.
The path whereby man derives light from the Attribute al-Qahhar is that one should view his nafs, which is ever present within him, as the worst of his enemies, so he subdues it and strangles it, doing exactly the opposite of what it tells him to do, so much so that it will have no choice except to submit to divine commandments.
Then he will have to subdue his stubborn opponent, i.e. Satan, staying on his guard against his evil suggestions, blocking his avenues. Then he will have to subdue his carnal desires and insinuations by not following what they inspire him to do.