What is truth you can rely on, and how do you find it?
Firstly I want to open by saying that a lot of what has been written on the topic of reason and religion can seem antagonistic. In fact a lot of it is.
I was a Christian. I understand why people are religious. I know what people get from religion.
I think what makes me different from many Christians, and I guess most people in general, is how important the truth is to me. Not only do I deeply despise liars, I am also tenacious when it comes to the truth -- I will ponder what I don't understand, in some cases for years; sometimes it's like a project to me, but sometimes it's because the back of my mind is not comfortable until the puzzle pieces fit. This truth is ultimately, not at first but ultimately, more important than the emotional investment in what may turn out to be false, or inaccurate. I think this last fact is what allowed me to let go of theism, and then deism. It has a name: 'Sunk cost'. And it feels unnatural, or fickle, to let go of things you have invested heavily in, especially emotionally, but understanding sunk costs is part of growing up.
Here is why it is important: Hope without knowledge is hopeless.
Every religion, including your religion, is based on faith. "First believe and then everything will become clear." "Search your heart and you will know it is true."
Why? Why does the truth of a religion depend on my heart? Surely there must be a way of establishing its truth regardless.
I think the official explanation is that God is absolute and eternal, and we are relative and mortal, and so there is no way to come to the absolute from the relative. No, we rely on the divine revealing itself to us, and this happens when we search our hearts: God reveals Himself to us.
But actually it's even simpler than that; ancient and established religions are to a large extent internally consistent. In other words, if you agree to the assumptions, then everything else makes sense. That is what your heart will reveal.
What took me a long time to realise, and then a long time to accept, is that those assumptions are not true.
And what makes it harder is that one of the first things any decent religion will do is make it illegal to inspect those assumptions. In the Old Testament, God forbids it, and punishes Jews who put Him to the test. And the Jews are reminded several times, in case it slips their mind.
The Unforgivable Sin (explained in Matthew and Mark) is to look at the work of the Holy Spirit and to attribute it to Satan. A naturalist, atheist or agnostic would never attribute something to Satan, of course, but attributing miracles to word-of-mouth embellishment, or misobservation, or lying, or just a lack of a complete understanding of the laws of nature -- anything but the spirit of God -- seems like cutting it a bit fine to me.
But naturalists, atheist and agnostics are brave men and women, with a proud history of bravery in a very antagonistic world. Ask Salman Rushdie.
They have to be. And they have inspiration: they are fighting for real truth. Not the kind that requires you to accept a set of attractive-looking assumptions first, and then search your heart.
No. Truth that you can rely on. Truth that you can test. Truth that will out. Long after your favourite god is relegated to mythology, become the name of a planet or constellation, and if he's really cool, maybe a Marvel Comic character, the truth of naturalists, atheist and agnostics will still be true.
How do we know that? Because we test everything we know. And if we ever find out that we were mistaken, we don't cling to our false beliefs, as clergy did when witchcraft was first abolished, and when slavery was abolished, because they are both (still) in the Bible. We do the opposite of clinging to false beliefs. We will enthusiastically work at finding a new explanation. And every time we find something new, we will determine ways to test it. And then, ruthlessly, we will throw everything we can at that theory, until we know we can depend on it.
And we are not selfish. Religious people can rely on our truths too. And they do, every day they put their lives on the line when using technology -- every time they drive a car faster than a few kilometres an hour, every time they fly in an aeroplane, or walk into a skyscraper.
To summarise, in almost the words of a beautiful, if slightly mistaken, piece of literature:
This is the way. This is actual truth. This is the only way to live: No one can get to the truth but through reason.