Why does the Lord's Prayer ask God not to lead us into temptation? Surely God wouldn't lead us into temptation, by his very nature; He doesn't *want* us to be tempted. So why do we have to ask?
The Greek used here means both trials that test us and temptation in the sense of allurement. However, according to most commentators, the usage as a trial of testing is the usual meaning in the New Testament, and the Epistle of James explicitly rejects that God lures us into sin (see James 1:13). Therefore, a trial/testing is the most likely emphasis in this passage.
In this prayer, we are essentially praying the same prayer as Jesus when he said, "If possible let this cup pass from me" (Matt. 26:39).
For this reason, some translations of the Lord's Prayer use "do not subject us not to the final test" or "do not bring us to the time of trial." However, in English, traditionally we have used the "lead us not into temptation" translation. In this sense, it is meant that being subjected to a testing/trial of our faith could tempt us to fall away from the Faith. It is an acknowledgment of our weakness and our need for courage and strength from God.