Okay, so we do assume that the universe is sufficiently consistent in the way it behaves that we can predict things about it. This assumption is implicit within the scientific method but is also commonly held by most beings living their lives outside of padded cells or the equivalent. We can’t prove it’ll continue to hold, so you can call it “faith” if you like.
Similarly, theists have “faith” that the Deities won’t spontaneously change their minds or their natures and put all the evil people in Heaven and the good people in a lake of orange custard, but again this assumption is usually considered implicit and rarely needs spelling out.
No you don’t. You believe because it worked last time, the time before and countless times before that. If you really want to encounter a chaotic and constantly changing universe, keep a dream diary.
Buddha/Sidhartha is not, strictly speaking, considered a divine figure, even by (most) Buddhists. Allah isn’t a proper name; it’s the Arabic term for God, and is used by Muslims because they believe the Qu’ran can only be read in the “original” Arabic. They acknowledge that he’s the God of the Jews and Christians, though- so when you refer to a general-purpose “God”, he’s covered.
