Thoughts about the Antichrist.

Did you know that Vladimir, being an illegitimate son of Svyatoslav, had no rights to the throne, treacherously killed his brothers with the support of Byzantium, and the condition for this support was precisely the adoption of Christianity by Rus'? I hope you know how the forced introduction of religion works. Not even using the example of Rus', but looking at later periods. How missionaries introduced Christianity in Africa and America...

The fact that Vladimir killed his brothers is unconfirmed (but, of course, likely). The idea that Vladimir used the support of Byzantium under the promise that he would spread Christianity is a hypothesis. The fact that the baptism of Rus' was difficult (but still much easier than with the Africans, because in our case, the prince himself was baptized, and you can't argue against his will) is a historical fact, perhaps the only one, and even then, the details are greatly exaggerated. You seem like an intelligent person; you should understand that at that time, a centralized religion was necessary. They tried to introduce Perun, but it didn't work, and then they started thinking and introduced Christianity, with difficulty, but they did it.
And don't disdain textbooks; in any case, you can read books by different authors and even foreign textbooks to compare information. It's still better than reading books by historians who have only a couple of hypotheses in their heads, like "Alexander Nevsky = Alexander the Great" (this is not a joke; it's a real hypothesis, although, for some reason, it doesn't enjoy much trust among most historians).
Almost forgot, Lochen, firstly, Islam and Christianity are largely similar; it's just that they have mullahs who are stubborn, and our priests are stubborn, hence the disagreements. In general, I think that all religions, in one way or another, imply the same God, they just call him by different names. Some find it easier to imagine him as a pantheon of gods, while others imagine him as a house spirit. It all depends on how you perceive the world.