There are some vague similarities between Islam and...

There are some vague similarities between Islam and Christianity, but even where there is overlap there is significant disagreement. For example, the portrayal of Jesus is different; Christianity claims that Jesus is the Son of God and all that entails; Islam specifically denies this claim, instead portraying Jesus as an important prophet along with other important prophets.

Muslims claimed that their sacred writings corrected errors in the Bible seeing some of these "errors" as blasphemy; Catholics are hardly likely to encourage a religion that made these claims and developed its doctrine based on them never mind starting one that made these claims.

The management structures of Islam and of Catholicism are completely different and certainly not evidence of a Catholic hand in creating Islamic management structures.

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I don't know who would be insulted more by the claim of Catholic hands in the creation of Islam; Catholics or Muslims.