Alongside Mill's idea has arisen the postmodern idea that truth is relative, and that truth claims are power plays meant to subjugate people. Throughout history, people who claim to know the truth tend to follow Al Capone's famous maxim: "you can get more with a kind word and a gun than you can with just a kind word." Theology, then, on a postmodern account, is just a power play, designed to give an elite class privileged status, or else merely an exposition of one's subjective ideas.
Standing over against this view is the orthodox Christian belief that Truth exists, is knowable, and is communicable. If Truth exists, and if God exists, then Theology is a category of non-fiction; that is, it describes, and attempts to describe accurately, something that actually exists.
Suppose you were writing a travel guide to a fantasy world. If the world was a product of your own imagination, then by definition whatever you said about it would be true. But if you're describing an actual place, like London, then your descriptions of it are either true or false. The statement "Piccadilly square is painted green" either accurately described Piccadilly square or it doesn't.
But now suppose that there are no boats capable of bearing us across the Atlantic and so nobody we know has ever been to London. Who can tell us what it's like?
The book of Job, the earliest book of the Bible, records what mankind has been wondering about God ever since the beginning:
"If only I knew where to find him;
if only I could go to his dwelling!"
"If only there were someone to mediate between us,
someone to bring us together..."
But the gospel of John tell us that even though no one can travel to where God is, there is One who came to tell us everything we need to know:
"No one has ever seen God, but the one and only Son, who is himself God and is in closest relationship with the Father, has made him known."
"No one has seen the Father except the one who is from God; only he has seen the Father."
And in 1 John it all comes together:
"Dear friends, let us love one another, for love comes from God...this is how God showed his love among us: He sent his one and only Son into the world that we might live through him. This is love: not that we loved God, but that he loved us and sent his Son as an atoning sacrifice for our sins...no one has ever seen God; but if we love one another, God lives in us and his love is made complete in us.
This is how we know that we live in him and he in us: He has given us of his Spirit. And we have seen and testify that the Father has sent his Son to be the Savior of the world. If anyone acknowledges that Jesus is the Son of God, God lives in them and they in God. And so we know and rely on the love God has for us.
God is love. Whoever lives in love lives in God, and God in them." (1 John 4:7-16)
Jesus claims to bring a firsthand account of London. Should we believe his claims? What should we make of them if we do?
That's Theology, the Queen of the Sciences. And if you've ever caught yourself wondering, "What's the point?" then nothing could be more relevant, or more timely.