According to Islam, every person is born upon fitrah , a natural inclination toward truth and belief in one God (tawhid). However, this does not mean a person is automatically a Muslim from birth.
I mention this because Shaytan seeks to lead people away from this natural state through deception and misguidance.
For this reason, by default, he is considered an enemy to all of humanity, since he works against the very nature with which humans are created.
> 30:30
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> So direct your face toward the religion, inclining to truth. [Adhere to] the fitrah of Allah upon which He has created [all] people. No change should there be in the creation of Allah . That is the correct religion, but most of the people do not know.
> "Every child is born on Fitrah (natural disposition), then his parents make him a Jew, a Christian, or a Magian.” [Sahih Bukhari & Muslim]
Are there any other reasons to make him evil to all humanity?
And what would happen if I made Iblis an ally ?