Consider it pure joy, my brothers, whenever you face trials of many kinds, because you know that the testing of your faith develops perseverance. Perseverance must finish its work so that you may be mature and complete, not lacking anything.
James 1:2-4 (NIV)
When training to prepare for war, soldiers will practice under conditions much like those they will face in battle. The training itself can be very dangerous and is a tortuous ordeal. Soldiers will practice nearly any conceivable situation so that they will be ready when they come face to face with the real life combat. The same goes for firefighters, police, astronauts, or anyone else who is facing life and death in their occupation.
We all are tested in our lives. Sometimes the testing comes in the form of hypothetical what if conversations with others. Other times we may recognize choices that we see before us or others that require wise moral judgment. Our training may come in the form of what we read or the entertainment choices we make. We may have questions and others may question us. The Christian walk consists of challenges to our faithfulness everyday. Just like a person may train at the gym to build stronger bodies, a Christian should always be in training to build up a stronger faith. The trials we face may be perilous and stressful, but each time we overcome one we are strengthened to resist the really big temptations that we may face later. We must always press onward to become better equipped in our faith.
Blessed is the man who perseveres under trial, because when he has stood the test, he will receive the crown of life that God has promised to those who love him.
James 1:12 (NIV)
A military hero has gone through the training and testing necessary to go successfully into battle. The soldier who becomes a hero has persevered to attain his rank and when he has proven his bravery under fire he may receive accolades and medals. An athlete in training will endure much physical stress, but they may be later rewarded if they win the contest in which they enter. When we endure our training as Christians and have stood firm against trials, tests, and temptations God will reward us for our efforts which demonstrate our love for Him.
When tempted, no one should say, "God is tempting me." For God cannot be tempted by evil, nor does he tempt anyone; but each one is tempted when, by his own evil desire, he is dragged away and enticed. Then, after desire has conceived, it gives birth to sin; and sin, when it is full-grown, gives birth to death.
James 1:13-15 (NIV)
God does not tempt us, but he has given us free will. We are each given a choice how to live and what decisions we want to make in our lives. God has laid out the rules for righteous living and it is up to us to play by these rules. Often we want to make our own special rules based on what we want or how we feel. These are the rules created by our evil or misguided desire. We should not fall into this trap because the consequences are very bad--the consequence is death. Doing wrong is sin and the wages of sin is death.
Let's look at it another way. Traffic laws have been enacted in order to create a safe environment for driving and to keep order on the roads. If everyone decided to just drive according to what they felt was right for them and to suit their wishes there would be chaos on the roads, accidents would be more frequent, and people would die. We have enforcement in the form of police and if we do not follow the laws we may get a ticket or even have our privilege to drive taken away from us. The rules have been made for a good reason and most of us resist the temptation to break them because we don't want to face unpleasant consequences.
One might try to argue against the laws set forth by God, but if one really studies these laws the logic is there and the logic is complete. The laws are based on good reasoning. One's own selfish desires may try to exempt them from some of these laws, but it doesn't really work that way. Think and reason thoroughly and you will see. But don't think too hard, because there is no really good reason to do so. Your selfish ambitions may deceive you into the enticements of your own desire, but this will come to no good end. Trusting in yourself will not ultimately save you, but trusting in God will.