Question:My Christian life hasn't been very fruitful to say the least. I still engage in the same sexual lusts that I once did and I am searching for the right book in the New Testament to commit to memory so that I can combat these temptations. I can't win unless I have the sword to battle with, the Word of God. Which book would you recommend, given the fact that I can't overcome sexual urges and lusts without the Word of God?
I always find the methods people develop to deal with the problem of sins within their life. Yours has at least some practicality, but the difficulty is that nowhere does God say that if you memorize a part of the Bible, your temptations will go away. As Paul warned, "These things indeed have an appearance of wisdom in self-imposed religion, false humility, and neglect of the body, but are of no value against the indulgence of the flesh" (Colossians 2:23).
So let's back up a bit and see where the problem can be attacked with success.
First off, you have to accept that sexual urges are a part of your human body in the same way that hunger and thirst exist. The mere fact that you have sexual desires means you are normal and that your body is working as it should. All physical desires have a purpose. Hunger reminds you that you need to eat and thirst reminds you to take in enough liquids. Even the sexual urges serve a purpose which are necessary for the proper functioning of your body.
The problem we face is that these normal desires are perverted and twisted by Satan in attempts to get us to sin. "Let no one say when he is tempted, "I am tempted by God"; for God cannot be tempted by evil, nor does He Himself tempt anyone. But each one is tempted when he is drawn away by his own desires and enticed. Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death. Do not be deceived, my beloved brethren" (James 1:13-16).
You cannot turn off your physical desires. You might ignore them for a while, but they serve a purpose and need to be satisfied -- but in a proper, righteous way.
You cannot stop Satan from tempting you. None of us have control over Satan. We can resist his temptations, but we cannot stop him from offering them. "Therefore submit to God. Resist the devil and he will flee from you" (James 4:7).
The real battle comes when a person gives serious consideration to a temptation and begins plotting how it might be accomplished without being caught. When a person so strongly desires something that he is willing to consider breaking God's law, then he has crossed the line into sin. "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 here where we can give resistance to the devil.
Having sexual desire is perfectly normal. Being confronted with temptations to do sexual sins is something we cannot avoid. But when we realize that it is wrong and reject it, then we are doing what God asks us to do. To feel guilty for being tempted or for having a sex drive is making something out to be sin that God never called sinful.
But if you want to study one book that perhaps contains the most advice on sexual sins and why they should be avoided, I would recommend the book of Proverbs. For a book on how to approach love, courtship, and marriage in the proper way, I would recommend the Song of Solomon.