Thanks for the clarification. I think that is true for many religious beliefs, but not all. I don't think it implies the scientist would no longer be religious, although I think that is your assumption.
If a scientist applied the scientific method to artistic claims of fact, do you think would they stop being an artist? Or no longer appreciate works of fiction? Why do you think they would give up religion if they applied the scientific method to their religious beliefs?
Not in the same way you do. The Islam claims you mention are not verifiable as true or false. You (I think) are assuming them false because you belief that no god exists, but this is an assumption on your part, not an established fact.
Individual works of art may or may not make claims of fact and Water Lilies is an example that does not. So how does this illustrate a distinction between religious claims of fact and artistic claims of fact?
Consider this work of art: (I just googled message art and found it, it has no particular significant to me)
http://www.ourhenhouse.org/wp-content/uploads/2012/09/0000s_0007_2011_10_10_art_with_a-353x210.jpg
It's clearly making a statement, primarily about ethics but there are facts being claimed as well. Can you articulate the difference you feel exists between this type of artistic claim of fact and religious claims of fact?