Every­one has warned me not to tell you what I am going to tell you in this last book. They all say ‘the ordi­nary reader does not want The­ol­ogy; give him plain prac­ti­cal reli­gion’. I have rejected their advice. I do not think the ordi­nary reader is such a fool. The­ol­ogy means ‘the sci­ence of God,’ and I think any man who wants to think about God at all would like to have the clear­est and most accu­rate ideas about Him which are avail­able. You are not chil­dren: why should you be treated like children?

In a way I quite under­stand why some peo­ple are put off by The­ol­ogy. I remem­ber once when I had been giv­ing a talk to the R.A.F., an old, hard-bitten offi­cer got up and said, ‘I’ve no use for all that stuff. But, mind you, I’m a reli­gious man too. I know there’s a God. I’ve felt Him out alone in the desert at night: the tremen­dous mys­tery. And that’s just why I don’t believe all your neat lit­tle dog­mas and for­mu­las about Him. To any­one who’s met the real thing they all seem so petty and pedan­tic and unreal!’

Now in a sense I quite agreed with that man. I think he had prob­a­bly had a real expe­ri­ence of God in the desert. And when he turned from that expe­ri­ence to the Chris­t­ian creeds, I think he really was turn­ing from some­thing real to some­thing less real. In the same way, if a man has once looked at the Atlantic from the beach, and then goes and looks at a map of the Atlantic, he also will be turn­ing from some­thing real to some­thing less real: turn­ing from real waves to a bit of coloured paper. But here comes the point. The map is admit­tedly only coloured paper, but there are two things you have to remem­ber about it. In the first place, it is based on what hun­dreds and thou­sands of peo­ple have found out by sail­ing the real Atlantic. In that way it has behind it masses of expe­ri­ence just as real as the one you could have from the beach; only, while yours would be a sin­gle glimpse, the map fits all those dif­fer­ent expe­ri­ences together. In the sec­ond place, if you want to go any­where, the map is absolutely nec­es­sary. As long as you are con­tent with walks on the beach, your own glimpses are far more fun than look­ing at a map. But the map is going to be more use than walks on the beach if you want to get to America.

Now, The­ol­ogy is like the map. Merely learn­ing and think­ing about the Chris­t­ian doc­trines, if you stop there, is less real and less excit­ing than the sort of thing my friend got in the desert. Doc­trines are not God: they are only a kind of map. But that map is based on the expe­ri­ence of hun­dreds of peo­ple who really were in touch with God-experiences com­pared with which any thrills or pious feel­ings you and I are likely to get on our own are very ele­men­tary and very con­fused. And sec­ondly, if you want to get any fur­ther, you must use the map. You see, what hap­pened to that man in the desert may have been real, and was cer­tainly excit­ing, but noth­ing comes of it. It leads nowhere. There is noth­ing to do about it. In fact, that is just why a vague religion-all about feel­ing God in nature, and so on-is so attrac­tive. It is all thrills and no work; like watch­ing the waves from the beach. But you will not get to New­found­land by study­ing the Atlantic that way, and you will not get eter­nal life by sim­ply feel­ing the pres­ence of God in flow­ers or music. Nei­ther will you get any­where by look­ing at maps with­out going to sea. Nor will you be very safe if you go to sea with­out a map.

In other words, The­ol­ogy is prac­ti­cal: espe­cially now. In the old days, when there was less edu­ca­tion and dis­cus­sion, per­haps it was pos­si­ble to get on with a very few sim­ple ideas about God. But it is not so now. Every­one reads, every­one hears things dis­cussed. Con­se­quently, if you do not lis­ten to The­ol­ogy, that will not mean that you have no ideas about God. It will mean that you have a lot of wrong ones — bad, mud­dled, out-of-date ideas. For a great many of the ideas about God which are trot­ted out as nov­el­ties to-day are sim­ply the ones which real The­olo­gians tried cen­turies ago and rejected. To believe in the pop­u­lar reli­gion of mod­ern Eng­land is ret­ro­gres­sion — like believ­ing the earth is flat.

From The Joyful Christian by CS Lewis

33 Oh, the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgments and how inscrutable his ways! 
34 “For who has known the mind of the Lord, or who has been his counselor?” 
35 “Or who has given a gift to him that he might be repaid?” 
36 For from him and through him and to him are all things. To him be glory forever. Amen.
1 I appeal to you therefore, brothers, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable to God, which is your spiritual worship. 2 Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect.(Romans 10:34-11:2 ESV)