Another source of temptation actually comes from within. James explains, "Let no one say when he is tempted, "I am being tempted by God"; for God cannot be tempted by evil, and He Himself does not tempt anyone. But each one is tempted when he is carried away and enticed by his own lust. Then when lust has conceived, it gives birth to sin; and when sin is accomplished, it brings forth death." Beware of the human nature. We are told in scripture that we are inherently evil, which is true. According to James, it is these unchecked human desires that draw us away from God and open us up to be tempted. That is why it is so important that we guard our heart, be careful about what we allow to enter our eyes and ears, and make sure we continue to focus on His purposes.
The third source of temptation is the world. Understand we are not of this world and that Satan is the god of this world (Corinthians 4:4). He has so designed a world system in which we are surrounded by every evil and vial thing possible and the bad thing about it is that Satan has made it look so beautiful and desirable. Constantly our senses are bombarded with things that our fallen human nature desires and honestly it is difficult to resist sometimes.
So, how should we deal with temptation? Obviously we can't remove ourselves from the planet or the world system nor does Jesus intend us to do that. In John 17 Jesus prays for his disciples, "I pray not that thou shouldest take them out of the world, but that thou shouldest keep them from evil. . . Sanctify them through thy truth: thy word is truth." We are to be an example in this world and even though we are in it, we are to set ourselves apart. The bedrock of all that we are as Christians is the Word of God. In it we will find the guidance, direction, and strength. Remember, Jesus responded to temptation by using God's word, and it wasn't that he had just memorized it, HE LIVED IT OUT! That gave power to His words.
We overcome temptation first of all by remaining focused on Christ and His purposes (Hebrews 12:1-4; Timothy 2:3-4). It is when we allow ourselves to lose sight of God and allow our priorities to shift from His purposes to the immediate things of this world that we begin our slide into temptation. Remember, we are told to pray that we are kept from temptation and we do that by staying focused.
The power of the word lived out can not be overcome. It is vital that we use the word of God as a weapon in our attack of Satan. Notice, that we are to be attacking Satan. Too often Christians live in the defensive mode. It is there that Satan finds ways to snare us. It was when David should have been out fighting that he gave into temptation and slept with Bathsheba (Samuel 11). Be on the attack using God's word as your sword (Ephesians 6).
Look for ways out. . . If you happen to fall into temptation, first off know that God will use it to make you a better Christian, then simply remove yourself from the situation (Corinthians 10:13). Too often we try to battle Satan in our own strength, it was never meant for us to. Use Paul's advice to Timothy, "Flee youthful lust. . ." That is what Joseph did when he was tempted to sleep with his master's wife.
Finally, don't ever forget that you are vulnerable. Being vulnerable we must acknowledge our dependence on God continually. James tells us to submit to God and THEN resist the devil and he will flee. Paul himself admitted to struggles (Romans 7:18-25) and we will have them too. So it is not a matter of if you will fail, but when. To fully overcome failure in temptation, know 2 things; 1 - God never gives up on His children. 2 - Remain persist in your repentance, being able to forgive yourself and move on with God.