"For you have been called to live in freedom, my brothers and sisters. But don't use your freedom to satisfy your sinful nature. Instead, use your freedom to serve one another in love." Galatians 5:13
It's pretty easy to slip into sin. After all, that's our default human nature. We love our little sins, don't we? It's so easy to go back to your regular, old, sinful habits when no one is around. After all, its no big deal. Nobody's gonna know.
Now, I know what I sound like... Those silly cartoons, the ones with the demon on one shoulder, angel on the other. Doesn't mean that battle doesn't actually happen every time that you are alone.
In your subconscious, temptations run rampant. It's easy when others are around - we can be good for others. We can be the good example. But when you are alone, you're an easy target.
Our enemy knows this - this is his preferred time to strike. Pick off the member of the herd that is separated from everybody else. It is a classic technique, as old as time.
When we give into those sins, it pulls us down. It makes us feel guilty and all too often it separates us from God - because we let it. We all know that God forgives us our sins, but we aren't too anxious to go run to Him right after we have sinned.
Be careful when you are alone - know that you are in someone's crosshairs. Know that despite anything else that happens, God is still with you. The biggest mistake we make when we are alone is not sharing that time with our Maker. Temptations don't seem so insurmountable after you've spent time in the Word and talking with God.
"No temptation has overtaken you that is not common to man. God is faithful, and he will not allow you to be tempted beyond your ability, but with the temptation He will also provide the way of escape, that you may be able to endure it." 1 Corinthians 10:13
Notice the phrasing in this verse - "He will also provide the way of escape." The way. THE, singular. As in, there is only one way to escape temptation - His Way. We can resist some temptation on our own, but we can resist ALL temptation with God. He always provides a way.