"But among you there must not be even a hint of sexual immorality, or of any kind of impurity... Nor should there be obscenity, foolish talk or coarse joking" (Ephesians 5:3-4, NIV).
Brazen misuse of sex saturates our society and virtually every man is tempted sexually at some time or another, but it is important not to confuse temptation with sin. Even Jesus Christ "was in all points tempted as we are, yet without sin" (Hebrews 4:15). However if you hang around temptations, you will eventually sin. We are exhorted to "flee sexual immorality" and "flee ... youthful lusts" (1 Corinthians 6:18; 2 Timothy 2:22).
Don't be confident about your strength to resist sexual temptations. For example, indulging in soft-core pornography often leads to hard-core pornography and then addiction.
The Bible encourages men to develop strong moral boundaries and to actively avoid seductive and sexually aggressive women: "Run from her! Don't go near her house!" (Proverbs 5:8, Living Bible). Also note Joseph’s example when he ran from Potiphar’s wife who tried to seduce him (Genesis 39:6-12).
God knows what we see, hear and think, and He judges us accordingly. Jesus clearly instructs: "But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart" (Matthew 5:28).
Women can lust, too, but God made men to be more visually oriented so they are immediately tempted to lust by what they see. Women generally are slower to react, responding more to romance, relationships and touch. Provocative or erotic images should be avoided—in TV, movies, the Internet, magazines, advertising or elsewhere. Both men and women should ask themselves: Does God want me to see this?"
It is much easier to control thoughts if our memories are not filled with erotic images. We are called to bring "every thought into captivity to the obedience of Christ" (2 Corinthians 10:5) and Philippians 4:8 tells us how to do this -- by filling our minds with "whatever things are noble... pure," etc. (Philippians 4:8).
Though we will never be perfect in this life, God wants us to continually strive toward that goal and to be aware that one sin can lead to another.