27 “You have heard that it was said, ‘You shall not commit adultery.’28 But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart. 29 If your right eye causes you to stumble, gouge it out and throw it away. It is better for you to lose one part of your body than for your whole body to be thrown into hell. 30 And if your right hand causes you to stumble, cut it off and throw it away. It is better for you to lose one part of your body than for your whole body to go into hell.
~Matthew 5:27-30 NIV
The verses above are the words of Jesus Christ. I notice how He puts life to the old law "Do not commit adultery". Adultery as we understand is the situation when a spouse is having an affair or is involved in an act of infidelity. "But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart." The word lustfully indicates that action is not the gauge of morality, but rather morality is the driving force behind the action. Looking at a woman is not immoral but when you entertain a lustful thought or desire through the use of your eyes, according to the bible, is simply adultery. At that point you broke the law and you have sinned.
Sin begins in the heart, the throne of the Holy Spirit. We will all be judged according to the condition of our hearts. Jesus emphasized the strict importance of keeping the whole body blameless. If other parts of the body are used to feed the corruption of the heart then they should be detached from the body to protect the whole. "It is better for you to lose one part of your body than for your whole body to go into hell." God gave us the parts of our bodies so that we could worship Him while we enjoy this life and all of His creation. In this world there are things that come to our awareness through our God-given senses. The sad thing is - that awareness teases our selfishness causing us to desire the things that we sense. Slowly we transfer our worship from God to the things that we desire. We give up what is pure for the sake of satisfying ourselves.
Adultery begins when we let our desired-object take the place of God in our hearts. When a man looks at a woman lustfully, he desires her and thus hates his own wife. Therefore he sins against God.
God help my heart to choose your approval over my desires.