Some objections to the concept of prayer to the saints betray restricted notions of heaven. One comes from anti-Catholic Loraine Boettner:
"How, then, can a human being such as Mary hear the prayers of millions of Roman Catholics, in many different countries, praying in many different languages, all at the same time?
"Let any priest or layman try to converse with only three people at the same time and see how impossible that is for a human being. . . . The objections against prayers to Mary apply equally against prayers to the saints. For they too are only creatures, infinitely less than God, able to be at only one place at a time and to do only one thing at a time.
“How, then, can they listen to and answer thousands upon thousands of petitions made simultaneously in many different lands and in many different languages? Many such petitions are expressed, not orally, but only mentally, silently. How can Mary and the saints, without being like God, be present everywhere and know the secrets of all hearts?” (Roman Catholicism, 142-143).
**If being in heaven were like being in the next room, then of course these objections would be valid. A mortal, unglorified person in the next room would indeed suffer the restrictions imposed by the way space and time work in our universe. But the saints are not in the next room, and they are not subject to the time/space limitations of this life.
**This does not imply that the saints in heaven therefore must be omniscient, as God is, for it is only through God’s willing it that they can communicate with others in heaven or with us. And Boettner’s argument about petitions arriving in different languages is even further off the mark. Does anyone really think that in heaven the saints are restricted to the King’s English? After all, it is God himself who gives the gift of tongues and the interpretation of tongues. Surely those saints in Revelation understand the prayers they are shown to be offering to God. **The problem here is one of what might be called a primitive or even childish view of heaven. It is certainly not one on which enough intellectual rigor has been exercised. A good introduction to the real implications of the afterlife may be found in Frank Sheed’s book Theology and Sanity, which argues that sanity depends on an accurate appreciation of reality, and that includes an accurate appreciation of what heaven is really like. And once that is known, the place of prayer to the saints follows. **Got this paragraph from
catholic.com/library/Praying_to_the_Saints.asp
The rest of the article is good reading as well.