You have lost the debate

Meaning: By your failure to acknowledge vital facts and/or reasoning presented within a discussion:

• You have demonstrated that your objective in said discussion is not a search for truth but rather to convince others of your predetermined position (PP) – a contest of wills.
• You have lost that contest.

Explanation

Debate generally comes in either of two forms:

• Rational debate generally consists of two or more parties exchanging information in a mutual search for a better understanding of the truth.
• Competitive debate consists of two (or more, but not usually) parties who each attempt to make the most persuasive argument for predetermined conclusions.

Unfortunately, a debate cannot remain rational if any of the participants view it competitively. If your strategy is to defend your beliefs regardless of evidence rather than setting your beliefs according to what the prevailing evidence shows, then you can never learn, most of your beliefs will be wrong, and you won't be able to defend them rationally. You will therefore lose any rational debate in which you continue with this strategy.

Motives

It seems to be the case that people get into a certain mindset where they confuse loyalty to people with loyalty to ideas – they come to believe that if the group believes something, then believing something different is somehow a betrayal of the group. Every discussion becomes an opportunity to proselytize – to defend and spread the belief, and to be seen doing so – rather than a search for truth. Every debate is competitive rather than truth-seeking.

Counterfactual belief-systems therefore often encourage this sort of thinking, as it is the only way their beliefs are likely to survive.

You may be a victim of such a belief-system, and of those trying to spread it for their own gain – or you may be one of those who stand to gain, at the expense of others, from the spread of particular false beliefs.

Either way, you've lost the argument. You might want to think about your loyalty to your unshakeable beliefs, and consider whether that loyalty was truly earned or whether you have been tricked.