Intercessory prayer through the dead outside of Christ has no basis in Scripture.
After your abusive post to Salvation, I am inclined not to care what you think.
Perhaps it's because you have an incomplete Bible.
So he armed every one of them, not with defence of shield and spear, but with very good speeches, and exhortations, and told them a dream worthy to be believed, whereby he rejoiced them all. Now the vision was in this manner. Onias, who had been high priest, a good and virtuous man, modest in his looks, gentle in his manners, and graceful in speech, and who from a child was exercised in virtues holding up his hands, prayed for all the people of the Jews. After this there appeared also another man, admirable for age, and glory, and environed with great beauty and majesty. Then Onias answering, said: This is a lover of his brethren, and of the people of Israel: this is he that prayeth much for the people, and for all the holy city, Jeremias, the prophet of God. Whereupon Jeremias stretched forth his right hand, and gave to Judas a sword of gold, saying: Take this holy sword, a gift from God, wherewith thou shalt overthrow the adversaries of my people Israel. Thus being exhorted with the words of Judas, which were very good, and proper to stir up the courage, and strengthen the hearts of the young men, they resolved to fight, and to set upon them manfully: that valour might decide the matter, because the holy city, and the temple were in danger. 2 Machabees 15: 11-16
How can Jeremiah talk to Judas if Jeremiah was dead?