From time to time, one hears folks claim that they hold to their views because they found them in the Bible. For example, one hears claims from Roman Catholic apologists that they figured out that Roman Catholic theology was scriptural, and consequently became Roman Catholics.
One area where such a claim cannot be true (and there are doubtless many such areas) is in the area of prayers/communications/call them what you like, to departed Christians. The source of such doctrines is not the Holy Spirit speaking through Scripture.
Here are some questions to demonstrate:
1. If you are trying to communicate with a dead person who did not know your language during life, what makes you think that the person will understand your language now?
Answer: Not the Bible. The Bible provides no reason to suppose that dead people gain knowledge of new human languages.
2. If you are trying to communicate with a dead person whose body is far away from you, what makes you think that the person will hear you?
Answer: Not the Bible. The Bible provides no reason to suppose that dead people can hear people who are talking far away from their corpses.
3. If you are trying to communicate with a dead person who is very popular - such as Jude or Seraphim of Saratov, what makes you think that the person has the ability or availability to hear you?
Answer: Not the Bible. The Bible provides no reason to suppose that dead people can hear many communications that are made at the same time, or that can be available to hear communications in general.
4. If you are trying to communicate with someone who you believe is bodily in heaven, other than Christ, what makes you think that such communication is possible?
Answer: Not the Bible. The Bible provides no reason to suppose that anyone in heaven beside Christ can hear our communications.
Let's see how one Roman Catholic apologist (a lay apologist named Dave Armstrong) responded on similar issues:
Similar to (1) & (4):
Dave writes: "If it is objected that the dead saints cannot hear us, we reply that God is fully able to give them that power ...."(source) The problem with this response is that it is special pleading. There is no question that God can give the gift of tongues and interpretation of tongues, and even that he has done so. Likewise, there is no question that God can enable communication between the living and the dead. The question is whether there is a reason to suppose that God does give dead saints (or those who are bodily in heaven) such an ability. It should be clear that the answer to that question remains "not the Bible."
Similar to (2):
DA writes cites the "Cloud of Witnesses" of Hebrews 12:1 (source). The problem with DA's citation is that "witnesses" in that verse does not mean spectators, but testifiers. In other words, DA's citation is based on misconstruing an ambiguity that is present in English but not present in Greek or Latin. In English, a witness can be an observer or the one who is observed. In fact, the first sense has slightly predominated our usage. Nevertheless, the cloud of witnesses of Hebrews 12:1 are a cloud of the latter kind of witness - the kind we see (not in graven images, but in the pages of Scripture) and who testify to us (not by voices in our heads, but from the pages of Scripture). Of course, while the principle witnesses were taken from Scripture, we could add additional ones not listed in Scripture, to the same effect. We are surrounded by their testimony and it should encourage us. They stand as a memorial, not as judges.
DA, however, cites a contrary opinion: DA cites Marvin Vincent (calling his work "a famous, standard Protestant reference work") who acknowledges that witnesses do not mean observers, but who asserts that the idea that they are spectators is implied. This is the classic "argument from authority" fallacy. DA cites a broad reference work that is supposedly "standard" and uses that in place of a reasoned exegesis of the text. There's a reason why such an approach is taken: whether it is Vincent or DA making the claim, the claim cannot stand on the text of Scripture, because it fundamentally relies on the English ambiguity. DA (by Vincent) asserts that the idea of spectators is "the principal idea," but that assertion is not correct. The idea of encouragement is the main idea - and that encouragement is gained by the footprints of those who have run before, not by their observation from the stands, as DA/Vincent portrays the matter.
Similar to (3): How can Mary, as a human being, hear millions of daily prayers simultaneously, much less process millions of daily prayers?
DA's Response: "Very simple: the saints, being with God in heaven, are outside of time. That being the case, they simply have no problem of number and sequence as we do, since we are temporal creatures, and hence, severely limited in that sense." (source)
There are several important problems with the response, but the point to be made here is that the only aspect of the response that is derived from Scripture is that the saints are with God in heaven. The other aspect, that they are outside of time, is contrary to Scripture. Recall that the martyrs in heaven will ask the question: "How long ... before... ?" (Revelation 6:9-10) Such a question presumes both time and the martyrs' subjection to it.
It should be clear from the examples above that those who try to communicate with the departed do so without Biblical warrant. The practice of attempting to communicate with the departed is both futile and sinful, even though it is doubtless done with excellent intentions by many Christians who so practice.
It should be noted that a rebuttal to DA's multi-part argument for prayer to the saints has already been rebutted here (link).
May God be glorified by those whom He has made holy!