The Word of God should not only be a check on our thoughts, but the source of them, which is a far deeper thing. We see it in Christ, the only perfect One. He only could say, "By the word of Thy lips I have kept Me from the paths of the destroyer." "Thy word have I hid in Mine heart, that I might not sin against Thee." There is a preserving power in the Word, to keep the feet from sliding, which those only know who receive the truth in the love of it. Merely having the Word hid in the memory and mind will not do. There is no preserving power in that. There must be the action of the truth on the heart and conscience, separating from all defilement—otherwise its preserving power cannot be experienced.