I’ve never taken ‘love’ to exist on faith. I know it exists because I feel it. I sense it directly, even if it is internal (it’s chemical reactions after all, right?). Obviously senses can be tricked, but that’s a different kettle of fish (and besides, tricks still exist). A hallucination is still real in sense that you saw it happen, it just didn’t happen in the world around you.
It may be the case that all emotions are illusory (though I know love isn’t, because we’ve been able to study it), but then this entire existence could be illusory. It’s a good enough illusion to be consistent with how the universe works, so it may as well be real.
This is why it’s daft to argue against a person who insists that they ‘feel that god exists’. That’s fine. Nobody can categorically say they don’t, unless there was a way to monitor and quantify/qualify every emotion a human undergoes (and it seems that that would be possible).
I think the most important thing about love is, you can feel it, and someone else can feel it too. It’s validated through shared human experience. That’s how many religions seem to spread, actually. At least the Pentecostal christian varieties. They play on feelings of belonging and of gaining a higher purpose in life. Those feelings, I have no doubt, are very real chemical reactions. But it’s not rational to extend those feelings to become a basis for other claims.
Being in love with someone doesn’t make a relationship exist. Only in the most stalker-ish minds is that true. Instead the relationship itself is proof that the relationship exists. By doing the things that normally constitute what we refer to as a ‘relationship’.
It is true that we base a lot of things on trust. It’s entirely possible to come to true conclusions based on trust. But when means through evidence are available, doesn’t that have the better track record of discovering reliable conclusions? By a fluke I could believe that the bus will arrive at 10:45 and be right. And it’s true that the timetable may have given a different time. But if I could call a friend who’s already on that bus and ask them, why would I resort to making up times? This is a test that is repeatable too. If I believe in a different time each day that the bus will turn up, I may be true some of the time, but it would equally demonstrate that faith just doesn’t work most of the time. That’s because faith can only ever ‘discover’ things by accident.
I’ve been looking at how children acquire language lately, and I came across a few interesting experiments. One was a study on how the trustworthiness of a speaker effects novel word acquisition. Adults who had a track record of telling the children in the study misinformation were not trusted when they named ‘novel’ objects (objects the children had not seen before). And this continues throughout our lives. We base our knowledge on trustworthy news sources, trustworthy scientific journals, trustworthy people we meet in our day to day lives. Deciding how trustworthy a particular source is is one of the ways in which we reason, because we can’t possibly study every single minute detail of how life, the universe and everything works.
But this is a distinct action from ‘faith’. Faith is usually the result of trust. So one must decide whether a source is trustworthy enough through one’s rational faculties. Rationally, things like the Bible aren’t trustworthy sources. So if your religion is not based on a holy book, what is it based on? Faith alone is inadequate. You may trust the person who first told you about Jesus and how he can change your life. But then, with the weighty claims that religious folk make, it’s not like trusting someone a film or book will be good. Religious folk make claims about your soul. They make claims about who you may have sex with, and on what days you must rest, and what must be done to the genitalia of male children. These aren’t completely benign claims.
So a rational person should really think hard about the source of their faith. This is one of the most frustrating things for the scientific community I suppose - that they’re not considered a trustworthy source by religious people, despite having an excellent track record, and a strong desire to dispel misinformation. I suppose this is why you get global warming deniers, etc.