On falsifiability:"God answers prayers" completely unfalsifiable.
"God caused a global flood" this is falsifiable but there is no reason to take the whole of the Bible 100% literally, as all atheists do. The "earth" mentioned in Genesis may have referred to the territories that were known to the people of Noah's tribe.
"God cures cancer sometimes" completely unfalsifiable.
Conclusion, the existence of God is unfalsifiable.
"Unfortunately for Popper's original idea, most scientific hypotheses are not really refutable with certainty either. Notoriously, a hypothesis can be saved from refutation by tinkering with the rest of the theory. And even in an idealized, empirical setting in which experimental outcomes are unproblematically theory-independent, probability estimates are logically consistent with any data in the short run, even if such an estimate is understood to imply a limiting relative frequency of outcomes in the future data. The same is true of the hypothesis that there are only finitely many types of elementary particles to be discovered, the hypothesis that a system is chaotic as opposed to orderly, and the hypothesis that a given sequence is produced by a Turing machine rather than by some uncomputable process.
Popper's response (1968) was to reconceive falsificationism as an injunction against coddling pet views rather than as a criterion of success."
Kelly, K. T. (2000). Naturalism Logicized. In R. Nola & H Sankey (Eds.) After Popper, Kuhn and Feyerabend: Recent Issues in Theories of Scientific Method (pp. 177-210). Kluwer Academic Publishers.
"contrary to naive falsificationism, no experiment, experimental report, observation statement or well-corroborated low-level falsifying hypothesis alone can lead to falsification. There is no falsification before the emergence of a better theory"
Lakatos, I. (1970) “Falsification and the Methodology of Scientific Research Programmes” in I. Lakatos and A. Musgrave (Eds.) Criticism and the Growth of Knowledge (pp. 91-195). Cambridge University Press.
On scientific methods more generally:
"Ask a scientist what he concevies the scientific method to be, and he will adopt an expression that is at once solemn and shifty-eyed: solemn, because he feels he ought to declare an opinion; shifty-eyed, because he is wondering how to conceal the fact that he has no opinion to declare"
Medawar, P. B. (1969). Induction and intuition in Scientific Thought. American Philosophical Society.
“One of the most widely held misconceptions about science is the existence of the scientific method. The modern origins of this misconception may be traced to Francis Bacon’s Novum Organum (1620/1996), in which the inductive method was propounded to guarantee ‘‘certain’’ knowledge. Since the 17th century, inductivism and several other epistemological stances that aimed to achieve the same end (although in those latter stances the criterion of certainty was either replaced with notions of high probability or abandoned altogether) have been debunked, such as Bayesianism, falsificationism, and hypothetico-deductivism (Gillies, 1993). Nonetheless, some of those stances, especially inductivism and falsificationism, are still widely popularized in science textbooks and even explicitly taught in classrooms. The myth of the scientific method is regularly manifested in the belief that there is a recipelike stepwise procedure that all scientists follow when they do science. This notion was explicitly debunked: There is no single scientific method that would guarantee the development of infallible knowledge (AAAS, 1993; Bauer, 1994; Feyerabend, 1993; NRC, 1996; Shapin, 1996).” (emphases added)
Lederman, N. G., Abd-El-Khalick, F., Bell, R. L., & Schwartz, R. (2002). Views of nature of science questionnaire: Toward valid and meaningful assessment of learners’ conceptions of nature of science. Journal of Research in Science Teaching, 39, 497–521.
"The model of ‘scientific method’ that probably reflects many people’s understanding is one of scientific knowledge being ‘proved’ through experiments...That is, the ‘experimental method’ offers a way of uncovering true knowledge of the world, providing that we plan our experiments logically, and carefully collect sufficient data. In this way, our rational faculty is applied to empirical evidence to prove (or otherwise) scientific hypotheses. This is a gross simplification, and misrepresentation, of how science actually occurs, but unfortunately it has probably been encouraged by the impoverished image of the nature of science commonly reflected in school science." (emphasis added)
Taber, K. S. (2009). Progressing Science Education: Constructing the Scientific Research Programme into the Contingent Nature of Learning Science (Science & Technology Education Library Vol. 37). Springer.
"there is no one way to ‘do’ science. Methods and practices vary widely across fields, institutions, and individuals. Even the U.S. National Science Teachers Association (NSTA) asserts, contrary to decades-old school lore, that 'no single universal step-by-step scientific method captures the complexity of doing science' (National Science Teachers Association, 2000). Amidst this array of approaches to doing science, there exists considerable debate amongst the general public and academics from a range of disciplines about how to characterize scientific inquiry."
Grotzer, T. A., Miller, R. B., & Lincoln, R. A. (2012). Perceptual, Attentional, and Cognitive Heuristics That Interact with the Nature of Science to Complicate Public Understanding of Science. In M. S. Khine (Ed.). Advances in Nature of Science Research: Concepts and Methodologies (pp. 27-49). Springer.
“Pre-college students, and the general public for that matter, believe in a distorted view of scientific inquiry that has resulted from schooling, the media, and the format of most scientific reports. This distorted view is called THE SCIENTIFIC METHOD.” (emphasis added)
Lederman, N. G. (1999). EJSE Editorial: The State of Science Education: Subject Matter Without Context. Electronic Journal of Science Education, 3(2).
"This myth [of the scientific method] is often manifested in the belief that there is a recipe-like stepwise procedure that typifies all scientific practice. This notion is erroneous: there is no single 'Scientific Method'... Scientists do observe, compare, measure, test, speculate, hypothesize, debate, create ideas and conceptual tools, and construct theories and explanations. However, there is no single sequence of (practical, conceptual, or logical) activities that will unerringly lead them to valid claims, let alone ‘certain’ knowledge." (emphasis added)
Abd‐El‐Khalick, F., Waters, M., & Le, A. P. (2008). Representations of nature of science in high school chemistry textbooks over the past four decades. Journal of Research in Science Teaching, 45(7), 835-855.
"Activity without understanding seems to be a regular feature of classroom life for science students in American schools...Any plans for testing new frameworks for school science investigations would be poorly conceived, however, without taking into account the influence of the current paradigm of preference for educators—the scientific method (TSM)—and its role in allowing distorted images of science to be passed down through schooling practices."
Windschitl, M., Thompson, J., & Braaten, M. (2008). Beyond the scientific method: Model‐based inquiry as a new paradigm of preference for school science investigations. Science education, 92(5), 941-967.
"a focus on practices (in the plural) avoids the mistaken impression that there is one distinctive approach common to all science—a single “scientific method”—or that uncertainty is a universal attribute of science. In reality, practicing scientists employ a broad spectrum of methods" (emphasis added)
Schweingruber, H., Keller, T., & Quinn, H. (Eds.). (2012). A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas. Committee on a Conceptual Framework for New K-12 Science Education Standards. National Research Council’s Board on Science Education, Division of Behavioral and Social Sciences and Education.
“In Science for All Americans, the AAAS advocated the achievement of scientific literacy by all U.S. high school students...(American Association for the Advancement of Science, 1989). This seminal report described science as tentative (striving toward objectivity within the constraints of human fallibility) and as a social enterprise, while also discussing the durability of scientific theories, the importance of logical reasoning, and the lack of a single scientific method.” (emphasis added)
Schweingruber, H. A., Hilton, M. L., & Singer, S. R. (Eds.). (2005). America's Lab Report::Investigations in High School Science. Committee on High School Laboratoriers: Role and Vision. Board on Science Education, Center for Education, National Research Council.