What is the good of pretending to be what you are not? Well, even on the human level, you know, there are two kinds of pretending. There is a bad kind, where the pretence is there instead of the real thing; as when a man pretends he is going to help you instead of really helping you.
 C. S. Lewis, Mere Christianity (1952). copy citation

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Author C. S. Lewis
Source Mere Christianity
Topic pretending help
Date 1952
Language English
Reference
Note Adapted from a series of BBC radio talks made between 1942 and 1944
Weblink https://www.dacc.edu/assets/pdfs/PCM/merechristianitylewis.pdf

Context

“You are not a being like The Son of God, whose will and interests are at one with those of the Father: you are a bundle of self-centred fears, hopes, greeds, jealousies, and self-conceit, all doomed to death. So that, in a way, this dressing up as Christ is a piece of outrageous cheek. But the odd thing is that He has ordered us to do it.
Why? What is the good of pretending to be what you are not? Well, even on the human level, you know, there are two kinds of pretending. There is a bad kind, where the pretence is there instead of the real thing; as when a man pretends he is going to help you instead of really helping you. But there is also a good kind, where the pretence leads up to the real thing. When you are not feeling particularly friendly but know you ought to be, the best thing you can do, very often, is to put on a friendly manner and behave as if you were a nicer person than you actually are.” source