They make no specific request. They simply say that they will speak of each other to God. (Maleldil is, in C.S. Lewis's space trilogy, the space-dwellers' name for God the Son.)
Compare that notion of prayer with this, from Letters to Malcolm:
Of course I pray for the dead. The action is so spontaneous, so all but inevitable, that only the most compulsive theological case against it would deter me. And I hardly know how the rest of my prayers would survive if those for the dead were forbidden. At our age the majority of those we love best are dead. What sort of intercourse with God could I have if what I love best were unmentionable to Him? (Letters to Malcolm, p. 106)Lewis goes on to state the argument against prayers for the dead that the dead are no longer on the road, no longer developing, that "progress and difficulty" are no longer possible for them, and that therefore there is nothing for which to pray for them. In response, he openly states that he believes in Purgatory, and he gives his own theory of what Purgatory is.
But I am interested still more in the paragraph I have just quoted. A couple of years ago when a person I had known only on-line died, I found that what Lewis says there is true. On the day after he had died I was praying, and it was virtually impossible not to speak to God of him and to ask...something. It was psychologically incredibly difficult to feel that there was literally no point in talking to God about him, and with fellow human beings, talking to God about someone invariably means some sort of petitionary prayer. I have had the same experience recently with a loved one who died.
How can one go from praying earnestly for those one loves to having nothing to say to God about them? It is true that, if one doesn't simply believe in Purgatory, as Lewis did, one isn't quite sure what to say to God about them. One is especially unsure what to request. A fragment from the Book of Common Prayer seems suitable and such as even a die-hard Protestant might not mind: "And we also bless Thy holy name for all Thy servants departed this life in thy faith and fear, beseeching Thee that they may continually grow in Thy love and service." That'll work. "Continually grow in Thy love and service." This corresponds to a conjecture that Lewis makes on the way to his comments about Purgatory to the effect that even in heaven there might be a "perpetual increase in beatitude" gained by a process with its own "ardours and exertions."
I think, too, that it is possible to pray for someone without knowing precisely what to ask, leaving that in God's hands. It is in the realm of petitionary prayer for human beings that I feel most of all the truth of Romans 8:26-27: "For we know not what we should pray for as we ought: but the Spirit itself maketh intercession for us with groanings which cannot be uttered." How often, when praying for the living, must we leave in God's hands what we should pray, realizing that what we would request spontaneously might not be best? Or, if a friend is no longer present, as in the case of someone who has moved to another state, we might literally not know their present needs, but we ask that God would do all for their good. Can this be extended to the dead? I believe that it can. As Lewis says, only the most compelling theological case that the dead have nothing whatsoever to gain or to do in the afterlife would convince me that it is pointless, at best, to pray for them. In that case, I suppose that the most one could do would be to bless the name of the Lord for them--i.e., to thank the Lord for them. But do we, even we Protestants, have such a compelling case that the blessed dead have nothing left to gain? I think that we do not. It is not necessary absolutely to believe that the dead still have growth before them to pray for them. It is necessary only to think that it might be so in order to pray that God would do all for them that can be done, that God would draw them ever-nearer to Himself, would give them in a continual outpouring of Himself that unimaginable (to us) increase of beatitude, knowledge, and understanding that is now proper to their state.
Notice, too, that a doctrine that Scripture contains all that we need for salvation (some version of sola scriptura) is consistent with such a practice. For it is not necessary to our or to their salvation that we should pray for them in this way. Nor is it necessary to our or to their salvation that we should refrain from praying for them in this way. We already know that Scripture leaves much of our curiosity unsatisfied concerning the afterlife for those who are saved. We are told that we will be with Christ, that this is far better. We are told that we will "know even as we are known." But the sum total is much less than we should like to know, which is, surely, exactly as God intended it.
Now I will push the argument in the other direction, which is yet more delicate.
But first, a pause for Protestantism: I am of the opinion that it is at least somewhat theologically problematic for us to ask the saints to pray for us, and especially for our particular needs and requests. I hope that is not offensive to my Catholic friends, but it seems to me that, to assume that the dead can hear our intercessions, that they know our present state on earth, and that they are speaking of it to God is to attribute to the dead something uncomfortably close to omniscience and to give to them something uncomfortably close to prayer. I will not say that prayers to the saints are definitely and intrinsically idolatrous, but I will say that I think they raise the danger of idolatry, for to treat the dead in this way is to treat them "too much" as we treat God--as an invisible Personage, far greater than ourselves, who can help us in our need, to whom we fly for refuge, who is always present to us, who knows our needs and what is best for us, and to whom we should cry out.
I also disagree with the idea, which I have often seen expressed by Catholics, that certain dead saints have special influence with God the Father or with Jesus Christ ("Doesn't it make sense to ask a man's mother to intercede with him for you?"), so that by going to them we are making our prayers more efficacious than they otherwise would be. This conveys a notion that seems to me theologically false and even unsavory--namely, a notion of needing to be "in with the in crowd" theologically rather than being loved fully by Our Lord oneself and being able and encouraged to approach Him directly with one's petitions. I note, too, that this notion of special "influence at court" is at odds with the other claim one sometimes sees--namely, that asking for the prayers of the saints is entirely unobjectionable because it is just like asking one's friends on earth to pray for one. But in fact, we don't believe that our ordinary friends on earth have this exalted "influence at court" in the heavenly realm, such as we are encouraged to think of the dead saints, especially certain ones like Mary, as having! So the two defenses of prayers to the saints are in conflict.
Having now (sad to say) probably thoroughly succeeded in offending my Catholic readers, I shall proceed, like a good via media Anglican, to try to offend my Protestant readers. All that I have just said notwithstanding, love between ourselves and others does not, cannot, cease simply because death intervenes. If someone loves you on earth, does he cease to love you because he dies and goes to heaven? God forbid. It seems rather that his capacity for love for other human beings should increase with his increased knowledge of Christ and union with Christ in heaven.
If, then, we find ourselves unable to stop praying for the dead simply because they are dead, since we still love them, might it not similarly be the case that the dead, at least those who have known and loved us on earth, find it impossible to stop praying for us? Just as we must speak to God of them, does it not seem plausible that they speak to God of us?
What remains is the question of what they know of us. Perhaps, as our knowledge of their state is blocked by the chasm of death, and we can pray for them only in the general terms suggested above, their knowledge of our situation is similarly blocked or greatly limited. They are finite beings, as we are, and we have no reason to believe that God has ordained that they shall have supernatural knowledge of all that is going on here on earth. As I already stated, to attribute that degree of knowledge to them seems to come uncomfortably close to making them demigods. Yet the blessed dead have no problem concerning us such as we have when praying for them--the problem of wondering whether there are difficulties still to face! They know quite well that we who are still in this vale of tears have many difficulties still to face, much sin in our nature, much needed growth, many dangers, toils, and snares ahead. On the other hand, it does not seem that the blessed dead should be able to experience worry or anxiety, which (one must admit) lies behind much of our own petitionary prayer.
So what would their prayers be like? Well, that is probably beyond our present ability to imagine. But, conjecturing, I envisage something like an outpouring of the entire self to God for the good of the other. We get a tiny glimpse of this in our own best prayers, perhaps for our children or for others whom, just occasionally, we begin to love with selflessness. And if such an outpouring is effective as prayer when uttered here on earth, why would it not have effect when uttered by one in heaven?
In other words, perhaps the dead really do pray for us effectually, and perhaps we really can pray for them effectually, even though we are absent from each other.
Imagine that someone whom you love has gone far away. He is still very much alive, and you know (in some way) that all is well with him, but you know very little else. He, in turn, knows that all may or may not be well with you, but he knows very little else of you. There is no Internet, no telephone, no physical mail. You are, in the ways of this world, separated from each other. Yet you both have the same Lord whom you love and to whom you pray. You have not ceased in love for one another. In those loves--for Our Lord and for each other--you are united despite the miles and limitations that come between you.
Might it not be, in some measure, like this with us Christians on earth and in heaven?
This is all conjecture, but it is conjecture befitting the season. If it is conjecture too timid for Catholic doctrine and too bold for Protestant doctrine, so be it.
I will only say this to those whom I love and who love me: Whether here on earth or absent from the body, speak of me always to Maleldil, as I will speak always of you.
For all the saints who from their labors rest,
Who Thee by faith before the world confess,
Thy name, O Jesus, be forever blest,
We feebly struggle, they in glory shine;
Yet all are one in Thee, for all are Thine.
Related post here.