Jesus Is Pure of Heart - from Henri Nouwen's Bread for the Journey
Jesus, the Beloved of God, has a pure heart. Having a pure heart means willing one thing.
Jesus wanted only to do the will of his heavenly Father. Whatever Jesus did or said, he did and said it as the obedient Son of God: "What I say is what the Father has taught me; he who sent me is with me, and has not left me to myself, for I always do what pleases him" (John 8:28-29). There are no divisions in Jesus' heart, no double motives or secret intentions. In Jesus there is complete inner unity because of his complete unity with God.
Becoming like Jesus is growing into purity of heart. That purity is what gave Jesus and will give us true spiritual vision.
For further reflection ...
"Your eye is the lamp of your body. When your eyes are good, your whole body also is full of light. But when they are bad, your body also is full of darkness. See to it, then, that the light within you is not darkness. Therefore, if your whole body is full of light, and no part of it dark, it will be completely lighted, as when the light of a lamp shines on you." - Luke 11: 34-36 (NIV)