It has been the case for many, many years, and is now, of course, even more so the case, that humanity's knowledge-base is so vast and varied that an individual is capable of understanding only the tiniest fraction of it. Specialists devote a lifetime to their little corner, and even then, at least in the sciences, will only make significant contributions by working collaboratively with others.
And yet we (or at least some of us) still hanker for a general understanding of things, a synoptic view. This is what religions and various secular ideologies have provided - something to satisfy our instinct to get to the bottom of things and to situate ourselves within the whole; to make sense of our fleeting lives.
Crucially, we need to integrate our feelings and values with our practical and objective knowledge of the world, and this is what religions and ideologies have done so successfully in the past.
Unfortunately, the most potent forms of religion today are completely divorced from modern science. Islam is locked into a medieval worldview, and the forms of Christianity (and indeed Judaism) which are currently flourishing rely on a blinkered and literalistic interpretation of scriptures composed thousands of years ago.
More intelligent forms of religion (like the views put forward by Erwin Schrödinger to which I recently alluded) are also problematic, in my opinion, largely because they tend to lack content. Rereading Schrödinger, I am annoyed both by the vagueness of his religious claims and by the patrician, sage-like tone. Just a bit too self-conscious. And of course the science is old.*
Political ideologies are not much more satisfactory. The complexity of the social realm makes it impossible to pin down the essentials in a creed or text, and attempts to do so - and apply the creed - have been spectacularly unsuccessful, often resulting in much unnecessary death and suffering.
But one can take the word 'ideology' in a broader sense, denoting a general set of beliefs about the nature of things and about social life and about what is important. In this sense, ideology is a good and necessary thing.
We need to make choices, we need to act, and to do so we need to integrate objective knowledge with feelings and values. I don't think we need to turn to religious traditions for help here (though many do); and of course we should be modest in what we claim for our view of things. But we need something like an ideology if we are to have a synoptic view, and certainly if we aspire to give a coherent and principled account of our actions.
* Interestingly, Roger Penrose contributed a brief preface to the reprint of some of Schrödinger's non-technical writings which I have been reading. Penrose writes that when he was a young mathematics student in the 1950s he didn't read a great deal, "but what I did read - at least if I completed the book - was usually by Erwin Schrödinger." It is no surprise that Schrödinger's mystical view of life and consciousness would have appealed to the man who was to write The Emperor's New Mind.