Faith which simply means believing without proving is dominant in religion. Consequently, it is often perceived to be an exclusive religious disposition. However, faith is not exclusive to religion. It is present anywhere there is believing without proving. Even in the most rational human endeavor, the scientific method.
Three key features characterize the scientific method:
(1) Observation and description of a phenomenon or phenomena
(2) Formulation of a hypothesis to explain the phenomenon or phenomena
(3) Performance of objective experiments (laboratory or mathematical procedures) so as to accept or reject the hypothesis.
Although all three aspects of the scientific method are necessary and important, the establishment of scientific truths is based on the acceptability of objective experiments.
Fundamentally, an objective experiment consists of three components: the objective, the experimenter(s), and the procedures. An objective, usually in the form of an hypothesis is stated. One or more experimenters interested in the hypothesis and with the relevant knowledge then seek to establish the acceptability or unacceptability of the hypothesis by carrying out repeatable procedures. At the end of the experiment, the hypothesis is either accepted or rejected or inconclusive. Depending on the importance of the hypothesis and the nature of the procedures, the experiment is independently carried out by various knowlegeable experimenters, if the initial investigation proposes its acceptability. If the scientific community accepts the hypothesis through this process of repeatable verification, the hypothesis is established as a scientific truth until an inconsistency is detected or until it is replaced by a better hypothesis (the knowledge-information continuum is not absolute everywhere because some of its regions are in flux).
Does an objective experiment fully guarantee the correctness of an accepted hypothesis? No. In each stage of an experiment, there is the chance of significant error: there may be yet undetected implicit flaw in the accepted hypothesis; there may be error due to experimenters and instruments of measurement; there may be procedural errors. Despite sophisticated error-smoothing techniques, the correctness of an hypothesis accepted through an objective experiment is not absolutely gauranteed.
Can an objective experiment be repeated always? No, not without the availability and willingness of knowledgeable experimenters. To repeat an experiment about a stated hypothesis, the experimenters must possess the required knowledge, be available and willing to conduct the experiment, otherwise the experiment cannot be repeated. Imagine a scenario where no experimenter is simultaneously available, willing and knowledgeable with respect to the repeating of an experiment about an important hypothesis which only one experimenter has confirmed. Such a hypothesis will probably not become a scientific truth until more experimenters with the required knowledge are available and willing to repeat the experiment and confirm the conclusion of the initial sole experimenter.
Objective experiments can not always be repeated by everyone since the complex processes and knowledge required to prove some scientific truths are beyond the reach of the general population. Consequently, in such instances, the general population believe without individually proving or even understanding what the scientific community has proved and understands. For example, the general population has not individually proved the existence of positrons: the antiparticles of electrons. So the less the general population understand the hypotheses and the objective experiments that accept them and the applications from them, the more the general population depend on at least a grain of faith in the scientific method.