The word in the New Testament that is translated temptation has the idea of testing metal to determine if it is genuine. Temptation can be defined as testing. We are told to pray to escape temptation.

And do not lead us into temptation, but deliver us from the evil one (Mat 6:13).

Purpose

God tests us to bring out the best in us while Satan tempts us to bring out the worst in us. Being tested or tempted is not sin—it depends upon what we do with the temptation.

Let us say, for example, that as you walk along your street you find a wallet. You look at the wallet and discover that it contains several hundred dollars in cash. There is also a driver's license and credit cards identifying the owner of the wallet. This constitutes a temptation. One could attempt to justify taking the money by saying the owner does not need it since he has numerous credit cards and obviously is financially well off. The temptation is not sin. What is done with the temptation determines whether the believer does or does not sin. If you return the wallet to the owner then you have not sinned. If you keep the money for yourself then it is a sin.

Expect to Experience Testing

Temptation, or testing is something that the believer should expect to experience.

These things I have spoken to you, that in Me you may have peace. In the world you will have tribulation; but be of good cheer, I have overcome the world (Jhn 16:33)

If you were of the world, the world would love its own. Yet because you are not of the world, but I chose you out of the world, therefore the world hates you. Remember the word that I said to you, 'A servant is not greater than his master. If they persecuted Me, they will also persecute you' (Jhn 15:19-20).

Trusting Christ as Savior does not relieve the believer from temptation. On the contrary there will usually be more things thrown in the Christian's path by the forces of Satan in order to make him fall. We should not think it strange when these trials cross our path. The Apostle Peter wrote:

Beloved, do not be surprised at the fiery ordeal among you, which comes upon you for your testing, as though some strange thing were happening to you (1Pe 4:12).

Summary

Temptation, or testing is something that the Bible says the believer will experience. God's purpose is to bring out the best in us while the enemy tries to bring out the worst.