To be called "narrow minded" is not the highest praise. It is an insult, typically associated with ignorance. By contrast, to have an open mind, purely for the sake of being open minded, is seen as a good thing. Realistically, however, the correct position should be somewhere in the middle. As fallible human beings, we should always be open minded enough to be teachable. However, being teachable also requires the ability to close our minds, keeping good ideas in and bad ideas out. Thus, it is bad to be closed minded because it makes one ignorant, and bad to be open minded because it makes one gullible.
This is particularly visible in the saying "seek the truth, but be wary of those who believe they have found it". This saying sounds wise and open minded. But note that it is a "truthful" statement. Not truthful in the sense that it is true, but in that it portrays itself as true. What it's saying is "I have found it to be true that those who say they have found the truth have not, in fact, found the truth".
Note also how it makes the pursuit of truth utterly fruitless! Are you really seeking the truth if, in order to appear open minded, you must reject the idea that you already have it? That's not seeking truth. That's intentionally closing your mind to it.
Of course, as a Christian, I believe I have found the truth. My God literally says "...I am the way, the truth, and the life. No one comes to the Father except through Me." (John 14:6, emphasis added). You have to be rather narrow minded to believe that, but you also have to be narrow minded not to believe that. You have to be even more narrow minded to tell others not to believe that.
Either Jesus is the way, the truth, and the life, or He is not. For me, believing that He is requires the rejection of all other views. I have to reject Islam, which says Jesus was only a prophet. I have to reject atheism, which of course denies there is a God, and thus Jesus, whoever He was, cannot be Him. I even have to reject fake versions of Christianity, many of which say Jesus is not the way, the truth, and the life.
But if you're "open minded" in that regard, the absolute most you can say is "he might be". And if you genuinely don't know, that's semi-acceptable. I say semi because of the logical law of excluded middle. Jesus either is the way, the truth, and the life, or He isn't; He can't be both. Therefore, if you don't say He is, you will live as if He isn't. True neutrality is impossible. Nevertheless, it is acceptable in the sense that you aren't just being blindly blown around by every wind of doctrine. Even Paul, of course taking for granted that the Scriptures are true, was pleased with the Bereans when they tested his Gospel against them, though he believed the Gospel was absolute, and that denial thereof results in eternal damnation. Thus, Paul says, "Test all things; hold fast what is good." (1 Thessalonians 5:21).
But note, "...hold fast what is good". As a Christian, having tested Christianity time and time again both before and after my conversion, I can say with complete confidence that Christianity is good. Many Christians around the globe can echo this testimony, including many whose minds were initially very much closed to the Gospel. So, we have two possible scenarios. If you tell me I should be more open minded, you are either saying "Christianity is not true", or "it might be, but it might not be".
In the former case, you aren't telling me to be open minded because it's wise, but because you have closed your mind to the Christian faith, as much as I have closed my mind to all other faiths.
But the latter is perhaps more arrogant. A closed-minded non-believer at least claims to know the truth for themselves, and pit their view against others. But those who, not knowing if Christianity is true or not, complain about Christians believing it is true, are effectively setting themselves up as the ultimate standard of truth! "I don't know, that means you don't either". I'll tell you this much: I would prefer a closed minded unbeliever than one who is so "open minded", he doesn't even believe it possible for another human being to know something he doesn't know.
You see, then, that there must be some kind of balance. There is no virtue in being open minded simply for the sake of being open minded, nor is there any major problem with being closed minded. We should never completely open or close our minds. Rather, what we all need is a good door man.
Sadly, as human beings, we all fail miserably at being good door men. From our youth, we allow awful, flesh-pleasing things into our minds. This produces all manner of unholy things. Gluttony, pride, sloth, wrath, and many other horrors, all of which lead us down a broad and dark path to death. But in His love for us, God did not leave us with only one way to travel. Through the blood of His Son, Jesus, God bought us eternal life, giving us a narrow path to eternal life.
Whereas the lies of the devil will take every opportunity to enter our minds, seeking every cracked window, testing every loose handle, even crawling up through the floorboards, Jesus knocks. But this knocking has two implications. It is a friendly invitation to let Him in, so He may fellowship with you, and bring with Him undeserved rewards; eternal life, and an everlasting inheritance in His Kingdom. But it is also a demand, as a police officer warning you that He is about to bring you in for your crimes. Each of us have sinned against our God, and deserves punishment. And if we refuse the friendly knock, rest assured He will blow down that door and deliver.
Sadly, many people, whether out of a desire to be so open minded their brains fall out, or out of a desire to close in their most cherished lies, will choose the broad path which leads to destruction. But while there is breath in your lungs, and blood pumping through your veins, you may choose the narrow path, leading to eternal life. Judge for yourself, which is the better option?