"And lead us not into temptation" is the sixth of the seven petitions in the Lord's prayer. The sixth request in the Lord's prayer is not to be in a place where temptation might overwhelm us. It is not wrong to be tempted or tested (Jesus was!). It is wrong to give in to this temptation.
Father Maximos, a Mount Athos monk, observes that the holy elders teach there are five stages in assaultive thoughts such as temptation. Logismos (these are thoughts and images that attack our thinking & lead us away from Christ) first assault our minds. For example, we may see something in a shop & be tempted to steal it. At this point no sin is committed (ideas and thoughts of sin happen to all people – even the holiest ones!) The next stage is interaction – we may then enter into a dialogue with this thought (for example, we may consider the risks involved). Again, no sin has been committed. The third stage is consent. A decision is made in the mind to give in to this assault. This is beginning of sin and leads us to acting it out. The next stage is captivity. When the temptation besets us again, we have much less resistance to these attacks and become addicted or controlled by them. The holy elders observer there is a fifth and final stage – passion. Here addictions (such as alcoholism or drug addiction) become obsessive and lead to self-destruction and harming others.
(Father Maximos teachings on this are outlined in greater detail in the book by Kyriacos Markides entitled “The Mountain of Silence”).
We can see from the above that the first and second stages – that of assault and interaction - is where we shall need to aware of Jesus’s words “lead us not into temptation”. This is where the battle ground is. If a thought is going to lead us down the path of destruction, we must ask God to “deliver us from evil” and give us the strength we need to resist this attack on our minds.
Verse 13. And lead us not into temptation] That is, bring us
not in to sore trial. PEIRASMON, which may be here rendered sore
trial, comes from PEIRW, to pierce through, as with a spear,
or spit, used so by some of the best Greek writers. Several of
the primitive fathers understood it something in this way; and
have therefore added quam ferre non possimus, "which we cannot
bear." The word not only implies violent assaults from Satan, but
also sorely afflictive circumstances, none of which we have, as
yet, grace or fortitude sufficient to bear. Bring us not in, or
lead us not in. This is a mere Hebraism: God is said to do a
thing which he only permits or suffers to be done.
The process of temptation is often as follows: 1st. A simple
evil thought. 2ndly. A strong imagination, or impression made on
the imagination, by the thing to which we are tempted. 3dly.
Delight in viewing it. 4thly. Consent of the will to perform it.
Thus lust is conceived, sin is finished, and death brought forth.
Jas 1:15. See also on Mt 4:1. A man may be tempted without
entering into the temptation: entering into it implies giving way,
closing in with, and embracing it.
Source: Adam Clarke's Commentary on the Bible