American culture is super-saturated with pornography and sexual temptations that are destroying our culture. Christianity is counter-cultural in that Jesus taught that to even think about committing adultery or using someone for your sexual gratification is a sinful act that will destroy you. Sexual desire is compared to a fire that must be kept under control and within the boundaries of marriage or it will spread like a wild fire and destroy your life.
The teaching of Jesus on this issue gets right to heart of the problem in that he addresses the intention of the heart of the individual. Even though you may not actually commit the act of adultery Jesus deals with the real cause, which is an internal problem with the thinking and heart motive of the individual. This was quite a revolutionary and counter-cultural message in light of all the rampant sexual behavior dominant within the Roman Empire at that time. The Kingdom of God deals with the heart issues that lead to sin and Jesus came to deal with the real issues that lead to the destruction of people. This is a hard message that resonates with real truth. To deal with sexual idolatry and corruption one must deal with their own heart desires which Jesus helps us to get right.