Nucleus
Abdullah Yusuf Ali's commentary: Kufr, Kafara, Kafir, and derivative forms of the word, imply a deliberate rejection of Faith as opposed to a mistaken idea of Allah or faith, which is not consistent with an ernest desire to see the truth. Where there is sch desire, the Grace and Mercy of Allah gives guidance. But that guidance is not efficacious when it is deliberately rejected, and the possibility of rejection follows from the grant of free will. The consequence of the rejection is that spiritual faculties become dead or impervious to better influence.
Be careful who you call Kafir because only Allah knows who is truly a rejector and who is merely a misguided person. It is not up to us to "sentence" a person to the Hellfire.
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