A new covenant in the bathroom

What is the prohibition against reading books about sex?

That's a different discussion. Here the question was about entering the services. Regarding the actual reading, there are circumstances that allow it. For example, someone who wants to study history, or someone who is hesitating about adopting Christianity themselves.

Why doesn't the name refer to God? After all, He is also the God of Christians?

Their God is triune and was revealed to Jesus.

So is the Quran forbidden to be brought into the bathroom?
B. When is the New Testament forbidden to be read?

Their God was originally round.
They believe in the Old Testament.

Is there a name in the Quran that says "H"?
It is forbidden to read when it is done out of an urge to join in his work. Even when there is a significant fear that it will have an effect, there is a reason to prohibit it.

I remembered that the response to the Letters of Moses, 13:13, discusses giving food to a secular guest who does not recite a blessing. In his remarks, he writes that even if he does recite a blessing, it is a blessing without the name of God.