Christians claim that the single God exists as three distinct persons: the Father, the Son, and the Holy Spirit. Muslims claim that this belief is false because several absurdities follow from it.
Al-Razi: Challenge to the Mujasima
In his Tafsir of the Quran, Imam Fakhr Al-Deen Al-Razi raises a question to the Mujasima and challenges them to answer it.
The Incarnation of the Immutable God
Christians claim that Jesus is God, who entered the world to die for the sins of man. Muslims claim that this is a false belief, because this is a change on the part of God, and it is rationally impossible for a beginningless being to change.
Ghazali: Tasalsul is Impossible
Tasalsul is the belief that the present moment is preceded by an infinite number of past events. In proving the existence of God, Imam Al-Ghazali offers three arguments for the impossibility of this belief.
Beginninglessness for God
You claim that it is impossible for the world to be beginningless, because Tasalsul is impossible. But shouldn’t this then also mean that it is impossible for God to be beginningless?
Keys to the Unseen 