History is plagued with ideologies. Religious ideologies, secular ideologies, political ideologies, batshit crazy ideologies.
For the early part of my life, I was obsessed with truth and correctness of ideologies. I found some which were close to being correct but none were immune from being manipulated into being wrong.
Later I realized a more useful function of an ideology than its correctness, and that was its ability to mobilize the irrational masses in synchrony and foster collaboration even under bad leadership and bad causes.
A mobilized mass of people is like having a computer which can execute instructions without question as long as it is justified by the ideology. So good ideologies need to be flexible so as to allow for a sort of completeness of access in the space of all possible social & political action without losing synchrony and mobility. Good ideologies should not punish hypocrites within its leadership, but it should preserve the misery of its followers so that they are mobilized to save themselves from it. Hypocrisy, at least among the leadership, is necessary so as to not make the leadership predictable and thus vincible.
Good ideologies need to offer meaning more than truth. This is because most people want meaning more than truth. People need a grand narrative we are part of, and marching towards the end of. Even scientists and skeptics have unstated beliefs like “equality of people is good” or “traditions are arbitrary and unnecessary”, to them the future (i.e. meaning) is an unstoppable march towards ever greater human equality and absence of traditional norms. These unstated biases compel them into creating a publication bias for politically correct truths. The peer-reviewed journals of truths they create, especially the parts of it which argue for human equality or progress are biased in favor of their unstated ideologies.
Good ideologies should be divided in labels, and unified in goals. e.g. feminisms. This is so as to make the ideology resistant to attack. Anyone who goes after many labels can be made to sound crazy. So we have the communists who are not same as socialists who are not same as who social democrats are not same as the progressives who are not same as the liberals who are not same as …
In the old days, good ideologies had to care about the fertility rates of its carriers. Modern ideologies do not need these features thanks to the virulence of modern media, and longer life expectancies. Therefore, features like early marriages, pre-marital celibacy, admonitions against the use of birth control, monogamy, quiverful-ness etc are not necessary for modern ideologies to maintain prevalence.
Ideologies enable collective action, which even when non-violent can make life difficult for the rest of us. There is utility in having connections and being able to trust each other. Good ideologies enable that.