How well the devil knows our human weakness! There is no method, therefore, that he more frequently uses . . . than just to play on this problem of self as it is present in every one of us. The ways in which he does so are almost endless. He works on self in order to encourage pride. He tries to make us proud of our gifts, our brains, our understanding, our knowledge. . . .David Martyn Lloyd-Jones, The Christian Warfare : An Exposition of Ephesians 6:10 to 13 (Edinburgh; Carlisle, Pa.: Banner of Truth Trust, 1976), 334.
Another form which this evil can take stems from the fact that various desires always tend to arise from self—the desire for importance, the desire for position . . . All this leads above everything else to a sprit of self-satisfaction . . . Furthermore this condition leads to selfishness and self-centredness. Self is always interested in itself. Everything revolves round this particular entity; and it becomes the centre of a constellation. That in turn leads to jealousy and envy . . .
To the extent that we are governed by self we are sensitive, and as such we can be easily hurt, easily depressed, and discouraged. Self is always watching for insults and slights. It is always hypersensitive. It is delicate, it is sensitized to everything; the slightest speck troubles it and alarms it. Self is totalitarian; it demands everything, and it is irritated and hurt if it does not get everything. As a consequence it becomes a most fruitful cause of quarrels and divisions and unhappiness . . .
If you have a great brain, it is no credit to you, you were born with it. If you have a wonderful singing voice, you have not produced it, it was given you. What are you boasting about? All that you have is not the result of your action and activity; it is something with which God has endowed you . . .
Paul always kept the grace of God in view; it kept him humble; it kept his spirit sweet; it kept him from the horrible sin of self and of pride and self-importance. Christians have nothing to boast of. We are what we are entirely as the result of the grace of God.