Matthew 5:28-30
But I say to you, everyone who looks at a woman with an improper sexual desire for her [body], has already been sexually unfaithful to his mate in his heart.
Mark 9:47
And if your eye becomes the occasion for falling away [from God] gouge it out; it would be better for you to enter the kingdom of God with [only] one eye, rather than keeping both eyes and being thrown into hell [i.e., all because one of them caused you to fall away from God].
1 John 2:16
For all that makes up the world, namely, the improper desires of the physical body, the improper desires for what is seen, and the [boastful] pride over life's possessions; these are not from the Father, but from the [godless] world.