How can modern people becomes sure enough about their beliefs, for this to be strongly motivating? Example from my earlier life as a scientist

We need to be sufficiently sure of our bottom-line convictions that they will serve strongly to fuel our personal motivation - so that we have the clarity and courage to aim at good; and to discern and navigate through life. 

But we modern people, in this modern world, find it very hard to believe in - anything!

At least, we moderns don't believe in stuff strongly enough that we can be truly free, and choose God and divine creation, and have the courage to stick with this --- in the face of a world that continually subverts, ridicules, suppresses, persecutes... and even inverts such intentions. 

We need true beliefs - i.e. beliefs that reflect reality (divine reality); and we also need to be subjectively sure about these beliefs in order that they can be positively motivating.

So how can we discover, and become sufficiently-convinced, by such things?  

The short answer is "intuition" - but I need to explain what I mean by intuition. 

For this I will here use the example of my earlier life as a scientist. 

When I began learning science, in the "early" phase;  it was learning "about" science; and I learned it in just the same way that we learn most other things about this world: we are told it we absorb it in terms of the assumptions that lie behind the functioning of our world. 

And we generally believe what we are told, especially when it comes from socially-defined authority figures.

But such "early" learning is superficial and passive - and such beliefs are not strongly held, not least because they have never really been understood, and we have never invested anything very personal into them. 

Consequently, these early beliefs concerning science were easily revised, modified, even reversed - when some "higher" authority said so. 

So: this early kind of passive and external belief about science was only very weakly inwardly motivating, and was unstable.

The same applies to all such beliefs - and this accounts for almost all proclaimed political, social and religious beliefs. They are shallow, impersonal - and very easily redirected or reversed by a change in what "authorities" are currently-saying. 

When I became a professional scientist, and began to do research; I entered an intermediate phase. I soon became much more discerning about what I believed, and more active in choosing who I would personally regard as authorities.  

My own understanding became deeper; albeit in externally derived terms. 

The doing of science became much more selective - but what I selected-from, and the criteria for regarding something as true; was something I assembled from that selective sample of what "authorities" stated.

I was not doing original or creative work in science; rather I was trying to be more professional, more discerning, and to do my work at a higher level than others. 

At this intermediate level; the work I was doing was not really anything to do with "reality" - rather it was dictated by the scientific literature - and was a matter of filling in gaps, extrapolating from what had already been done - and refuting pieces of established science that were (I believed) refuted by better authorities. 

It could be said I had "faith" in science as a process, as a social activity. This is analogous to most Christians "faith" in their church. 

I changed my mind less often than in the early phase, because I was more motivated - but this motivation was very much bound-up with and shaped-by the professional scientific environment - which was regarded as the ultimate arbiter. 

So, at this intermediate level; science was what the best scientists were saying (or had said) - and the intent was to become one of these "best" - and this was determined by the higher professional structures. 

Such a vision of science is this-worldly, and its standards and motivations are of this-world - even if rather idealized within this-world.

The motivations are stronger, because of the personal investment in the process; but the motivation is still ultimately external - and when the external consensus of those I regarded as "best" scientists changed, then so would my own purposes and motivations. 

I could (I hoped!) stand in a select company which I had partially chosen to ally-with; but I could not stand alone.  

The highest level of science was concerned by transcendental ideals that looked beyond the scientific milieu; ideals to do with reality (not just the relevant scientific literature) and truth (not just professional standards. 

At this highest level I was compelled to take personal responsibility for my beliefs; and might therefore need to "stand alone" when I thought that "the external world of science" (even of the best scientists, and by my evaluation) was wrong and misguided. 

For these evaluations to become beliefs that were strong enough to motivate; I needed to have criteria for conviction that went beyond my interpretations of the external world of the professional scientific literature. 

At this point, as may be clear, I had actually moved outside of the professional system of science. 

I had come to recognize that science had its assumptions that were not really true; that it was a matter of models not reality; and that for science to be true and real, required that science be understood in terms of ultimate reality...

Which included God and divine creation, and myself as having some personal significance in this.  

This was the point at which I developed sufficiently strong a personal motivation that I could, where I regarded it as necessary, maintain my convictions and direction without support from other scientists. 

I was, in other words, innerly-motivated, and also (consequently) more strongly motivated. 

This stronger inner motivation came from a different quality of conviction concerning what was true. 

At the early and intermediate levels of science; I was dependent on external authority as expressed in external communications and externally-validated interpretations of these communications - i.e. my belief (hence motivation) was rooted the observations and theories to be found in some selective sample of the scientific literature...

To reiterate - this understands science as communications that are externally derived and externally validated. 

At both early and intermediate levels; my convictions could be no different-from, deeper-than, or more-solid-than these external factors.  

And when these external factors vacillated, or even apparently reversed - then there was no alternative but for me to revise my convictions. 

This situation is demotivating! - especially when, by criteria external to science (and to do with truth and reality) science is being corrupted, as was very obviously the case.

(Science began explicitly to serve the needs of bureaucracy, careerism, politics etc. I could not fool myself other than that this really was corruption!)   

For me to have a personal conviction and motivation in science; I needed to have an inner sense of truth and reality; what is more this inner sense needed to be direct, not a communication; needed to be self-interpreting - not dependent on observations and theories. 

In other words "intuition". 

Actually, I have put matters the word way around; because it was only after I had recognized that intuition was and ought to be the root of science, that I moved to the higher level. 

What happened was that I would be thinking about something, working on something; when I realized that "this was it". 

From the stream of superficial thinking and doing, there sometimes emerged, there was discovered, a solid sense of conviction and surety; a "this is it".  

  

After a while, the intuition of "this is it" became the final validator of my work - unless I got it, and unless the sense of this-is-it was solid enough to survive repeated consultations; then I was not convinced. 

Lacking such an intuition; I remained unsure. 

I knew that "more work was needed". 

But with this intuition, and so long as it lasted and was operative - I was highly motivated, and could withstand any amount of external contradiction. 

To generalize from this specific experience; when we regard the external world as corrupt, and increasingly taking the side of evil; then unless we are to be drawn-into that; we need to move "above" considerations of the external, the communicated. 

We need, I think, to operate from the kind of deep intuition I eventually found in doing science...

Because only this intuition can be the basis for us to be free and positively-motivated by something outwith "society" that is both solid and potentially real.