I think there is a significant difference. If you were to say to yourself the Lord’s Prayer, and you get to the end where it talks of “deliver me from…” what do you say next? Do you say “evil” or “the evil one”?
Some questions about this were raised in today’s Greek class. The phrase used is tou ponerou, which is in fact ambiguous. It could mean ‘of evil’ or it could mean ‘of the evil one.’ So how can we decide what it means? Can there be a definite answer given? Some say no, but I say yes. Just see…
In another of Matthew’s usages of this phrase, found in the parable of the Wheat and the Tares (Matt. 13:36f), Jesus divides up the world into two mutually exclusive camps:
the field is the world; and the good seed, these are the sons of the kingdom; and the tares are the sons of the evil [one] –Matt. 13:38
This kind of labeling of two opposing camps is very common in the Judaism of Jesus’ day. Take for example one of the many occurrences found in the Dead Sea Scrolls:
the men of the lot of Belial -1QS 2.4-5
the men of Belial -1QH 13.26
all the lot of Belial -1QM 1.5
Belial, for those who aren’t familiar, is a name synonymous with the Devil and Satan. Paul uses it in 2 Cor. 6:15 as the antithesis to Christ, similar to what we see in the parable. There are other examples found in the Jewish Pseudopigrapha.
My point is this: we can see that it was very common during the time of Jesus for Belial, a synonym of the Devil, to be used as a way of categorizing a group of people. This makes sense with the parable of the Wheat and the Tares, where Jesus specifically speaks of the devil in v.39. Therefore, if Matthew uses tou ponerou to mean “of the evil one” within his Gospel, it is highly likely that he has the definition in mind in the Lord’s Prayer.
What do you think? Does it make a difference if you pray for deliverance from ‘evil’ or deliverance from ‘the evil one?’
 BDAG 173.