A well known quote from Robert Murray McCheyne in a a letter he wrote, which was latter published in Memoir and Remains of the Rev. Robert Murray McCheyne [(Edinburgh, 1894), 293].
“The heart is deceitful above all things, and desperately wicked: who can know it?” Jer. 17:9. Learn much of the Lord Jesus. For every look at yourself, take ten looks at Christ. He is altogether lovely. Such infinite majesty, and yet such meekness and grace, and all for sinners, even the chief! Live much in the smiles of God. Bask in his beams. Feel his all-seeing eye settled on you in love, and repose in his almighty arms. . . .
. . . Let your soul be filled with a heart-ravishing sense of the sweetness and excellency of Christ and all that is in Him. Let the Holy Spirit fill every chamber of your heart; and so there will be no room for folly, or the world, or Satan, or the flesh.