Do you find lectures on religious texts monotonous and boring?

Nope.  I study religions as a hobby.

It really depends upon the person lecturing.  Even good subject matter can be rendered monotonous by the speaker.  Sometimes it is how they approach the subject, other times it is purely their delivery.  

Depends entirely on who is giving the lecture. Religion, in general, is one of the most fascinating aspects of the culture of humanity since the beginning. Every culture, without exception, has addressed the questions religion tackles.

You mean like bible study?
I always struggle to stay awake and I feel bad for it because I only attend those because my friend drags me along.

Usually it is the speaker, more than the text, that is boring.

That said, I much prefer reading the texts myself, over listening to somebody's interpretation of it.

It depends. 

depends on what theyre talking about

That's my take on lectures and lecturing in general, regardless of the subject matter.  Even topics that fascinate me can be killers if and when delivered in monotonous and/or poorly prepared ways. 
Conversely, a dynamic public speaker can revet my attention throughout an entire lecture. 

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