Dave Armstrong Catholic apologist says:
"The Bible teaches that those who die and are saved are fully alive, that they are aware of earthly affairs, and that they love us; therefore it makes perfect sense to ask for their intercession.
Protestants often ask Catholics a question that goes something like this: “Why would anyone seek the aid of a mere manager or underling, when he can go directly to the CEO himself?” The comparison is, of course to asking saints to pray for us when we can go “straight to God.” In this vein, they cite 1 Timothy 2:5 (“one mediator”). And the proper Catholic (and biblical) answer is, “Because we are informed in the Bible that the prayers of certain people are more effective than those of others”:
James 5:16–18: “The prayer of a righteous man has great power in its effects. Elijah was a man of like nature with ourselves and he prayed fervently that it might not rain, and for three years and six months it did not rain on the earth. Then he prayed again and the heaven gave rain, and the earth brought forth its fruit.”
This brings to mind other powerful intercessors, such as Abraham and Moses, whose pleas were so strong that they convinced God not to destroy entire cities or people. If then, the Blessed Virgin Mary were indeed sinless, it would follow (right from Scripture) that her prayers would have the greatest power, and not only because of her sinlessness but because of her status as Mother of God. So we ask for her prayers and also ask other saints, because they have more power than we do, having been made perfectly righteous (according to James 5:16–18).
Most Protestants are quite comfortable asking for prayers from other Christians on earth; why do they not ask those saved saints who have departed from the earth and are close to God in heaven? After all, they may have passed from this world, but they’re certainly alive––more than we are! Jesus alludes to this fact when He speaks of “the God of Abraham, Isaac, and Jacob,” stating that “He is not God of the dead, but of the living.” (Mt.22:32) And those in heaven no longer have any sin (Rev.21:27; 22:14).
If it is objected that the dead saints cannot hear us, we reply that God is fully able to give them that power––with plenty of supporting biblical evidence: 1) the “cloud of witnesses” that Hebrews 12:1 describes; 2) in Revelation 6:9–10, prayers are given for us in heaven from “saints”; 3) elsewhere in Revelation an angel possesses “prayers of the saints” and in turns presents them to God (8:3–4; cf.5:8; Tob.12:12,15); 4) Jeremiah is described as one who “prayers much for the people” after his death in 2 Maccabees 15:13–14. (cf. Jer.15:1) The saints in heaven are clearly aware of earthly happenings. If they have such awareness, it isn’t that much of a leap to deduce that they can hear our requests for prayer, especially since the Bible itself shows that they are indeed praying.
We must be careful to avoid silly cultural stereotypes of what heaven is supposedly like. Sometimes we picture clouds, wings, and harps rather than the intensely spiritual place (or state) that it is, which souls longing and burning in their desire for human beings to be saved. The saints who have died devote themselves to prayer for us, because they are perfected in love. They no longer play all the games that we play in order to ignore the spiritual dimension of reality.
A Protestant Might Further Object :
It is not clear how these Catholic practices are any different from the séances, magic, witchcraft, and necromancy forbidden by the Bible. When you come down to it, Catholics are still messing around with dead spirits.
The One-Minute Apologist Says :
Catholics fully agree that these things are prohibited, but deny that the Communion of Saints is a practice included at all in those condemnations.
The difference is in the source of the supernatural power and the intention. When a Christian on earth asks a saint to pray for him (directly supported by the biblical indications above), God is the one whose power makes the relationship between departed and living members of the Body of Christ possible. The medium in a séance, on the other hand, is trying to use her own occultic powers to “conjure up” the dead––opening up the very real possibility of demonic counterfeit. Catholics aren’t “conjuring” anyone; we’re simply asking great departed saints to pray for us. If they are aware of the earth, then God can also make it possible for them to “hear’ and heed our prayer requests. If this weren’t the case, then saints and angels in heaven wouldn’t be portrayed as they are in Scripture: intensely active and still involved in earthly affairs.
“The consoling thing is that while Christendom is divided about the rationality and even the lawfulness, of praying to the saints, we are all agreed about praying with them…You may say that the distinction…is not, after all, very great. All the better if so. I sometimes have a bright dream of reunion engulfing us unawares, like a great wave from behind our backs.” (C. S. Lewis)