James1:14 Temptation comes from our own desires, which entice us and drag us away. NLT
Whenever I come across believers that complain of being tempted in a particular area of their life, I make it plain that temptations come from the carnal desires in our hearts that aren't dead yet. To be honest with you, we all still have certain desires in us that needs to be dealt with by the word and prayers. No man is tempted outside his carnal desires. If a man falls into adultery, the desire for immorality has been lurking somewhere.
Our temptation resistance level differs simply because our walk with God and submission to God's word differs. Any believer that carries his cross daily and deny self on daily basis won't have much problems with temptations because the carnal desires that attracts temptations are as good as dead. In fact, the sins that you commit the most as an unbeliever may still stare at your face after salvation.
If you haven't built enough resistance you may fall. The wisest thing to do as believers is to know what our weaknesses are and build a defense around us. If you are a chronic womanizer before you met Jesus, it would be unwise to surround yourself with a lot of young girls, you maybe writing letter to immorality. As you renew your mind with God's word, the carnal desires that attracts sin would be kept under.
Father, I receive grace to deal with carnal desires that wants to pull me down In Jesus name.