A friend recently asked me if it was appropriate to pray for the devil. When I first read it (in the text message) I thought that there would be an easy answer that would fit in 160 characters, but as I pondered my response I realized I couldn't provide a sure answer of yes or no with a brief reason why. I spent some time thinking on the topic (although honestly not too much because I received the question in the middle of a serious college basketball watching session) and still don't have an answer that I am sure about. My thoughts on the topic are as follows:
[please note that my thoughts on this topic are exactly that; thoughts and nothing else. I speak with no authority and very little scholarship on the matter. This is just me thinking through the topic.]
At first is seems like a charitable thing to do. After all, most Christians would say that it is reasonable to pray for those who have done or are doing something wrong. However, to pray means to ask, and if one were to pray for the Devil that implies that one would be asking something of God, some favor to do with the Devil. (For example, I might ask God to help person A with some struggle, to change something about their life. The devil in this context is person A). If I were to pray for Satan, what favor would I ask of God toward him? That he be forgiven? That he turn from his evil ways?
To be able to answer the question, it is important to address the possibility of the devil's repentance or forgiveness. Can he repent? Would he?
Repentance implies a change over time which I'm not sure applies to Satan. Because he is a spirit(non-tangible) being like God and the rest of his angels, there is no passage of time. (this is different from time passing forever. In this sense there is no time to pass. Everything is one existing instant) If he were repentant he would be eternally repentant which means we wouldn't ever have experienced this mess of sin. Following this, the question of will he repent doesn't even makes sense, so praying for something that can never be seems foolish. There is however more to consider.
Would he repent if it were possible? One thing to establish first is whether God would forgive him. Yes. God in His infinite mercy would forgive Satan, but I feel that Satan in his infinite stubbornness and rebellion would never repent. (His rebellion is infinite because someone with such perfect union with God as Satan would have had as a condition of being one of God's angels would have had perfect knowledge of the situation and therefore could not be said to have acted unwisely out of ignorance. Since he had no ignorance in the consideration of his decision then he can have no less than complete and infinite commitment to his desire to be better than God.)
We, as mortal, time constrained beings pray for things because we have hope that things might be different. In this situation however, because there is no "future" to be different, there can be no hope in a different future.
In conclusion, although it seems harsh and unforgiving to not pray for Satan since Christianity insists that we do such charitable things, I feel that this is a special case in which it is not warranted.
This is by no means a proof against praying for Satan. I might be wrong.
Also, I think that if someone felt the other way and chose to do so, even if it turned out that I am correct, God would consider their charity a merit and not hold it against them.