Periods when we make major changes in our life are always difficult. We have so many habits that we develop to make our life easier. Now, in a new situation those same habits can cause us difficulty or even harm.
Young men and women spend a good deal of time searching for a mate. Every single person you meet is automatically weighed as whether they are potential partner material or not. But that need is no longer there once you are married. The problem is that the habit is hard to break.
Lust is defined as a very strong desire. Typically we reserve it for a very strong desire for something that is unlawful to have. When Jesus condemned looking at women, "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), it is the lust that accompanies the looking that is the problem. If looking alone was a problem then we all would need to wear blinders because we live in a world full of people. But when a guy looks at a gal wonders what she would be like in bed, well, that is sinful because they aren't married.
Early in a marriage a husband and wife are still working on their basic roles and relationships. You might think you're in love now, but after 25 years of marriage I can look back and tell you that you haven't even scratched the surface of love yet. Just like a person in the first few weeks of a new job or a student at a new school, or anything else where you are new and don't know the full dimensions of what is expected of you, there is a lack of confidence in yourself. Early in a marriage one spouse doesn't know the full extent of how far they can trust the other person -- there is no experience to fall back upon. The desire to trust is there, but the surety hasn't appeared yet.
"Love suffers long and is kind; love does not envy; love does not parade itself, is not puffed up; does not behave rudely, does not seek its own, is not provoked, thinks no evil; does not rejoice in iniquity, but rejoices in the truth; bears all things, believes all things, hopes all things, endures all things. Love never fails" (I Corinthians 13:4-8). Trust is a foundation in a loving relationship, but trust is something earned when a person demonstrates over and over again that he is trustworthy.
You might follow a young woman with your eyes, thinking that she is quite attractive and nothing more, but your wife sees you looking and cannot read your thoughts. She is not fully confident in her position. She has a strong desire to trust you, but there is no track record to bolster her confidence in you. Thus in small ways doubt creeps into a relationship. It will fade in time as you prove your trustworthiness, but then why give room for doubt?
When Paul had the churches send relief funds to the needy saints in Judea, he insisted that each congregation select someone to carry the funds. It wasn't that the apostle Paul wasn't trustworthy. Rather, it was the simple expedience of not giving nay-sayers any room to spread doubt. "And we have sent with him the brother whose praise is in the gospel throughout all the churches, and not only that, but who was also chosen by the churches to travel with us with this gift, which is administered by us to the glory of the Lord Himself and to show your ready mind, avoiding this: that anyone should blame us in this lavish gift which is administered by us -- providing honorable things, not only in the sight of the Lord, but also in the sight of men" (I Corinthians 8:18-21).
In the same way, you need to be aware that it isn't just what you think or what you declare that is going to make an impact on your wife. The little things you do, even without thought from habit, are going to be seen by others. It is time to break old habits and establish new ones. Like Job of old, "I have made a covenant with my eyes; why then should I look upon a young woman?" (Job 31:1). If nothing else, it will help eliminate one avenue of temptation in your life. So make sure that you watch your wife. Take a moment when your across the room to glance at her. Let her see the smile on your lips when you make eye contact with her. When you are introduced to someone, make sure you include your wife as part of the introductions. When it is time to leave the room, get your wife to accompany you. They are good habits and those little things will tell her and others who is important in your life.