Dead people do not know anything, they have no memory, and they are unable to come back to earth as spirit. Thus, dead people do not hear our prayers.
Ecclesiastes 9:5 ... For the living know that they shall die: but the dead know not any thing, neither have they any more a reward; for the memory of them is forgotten.
Isaiah 26:14 ... They are dead, they shall not live; they are deceased, they shall not rise: therefore hast thou visited and destroyed them, and made all their memory to perish.
Luke 16:26 ... And beside all this, between us and you there is a great gulf fixed: so that they which would pass from hence to you cannot; neither can they pass to us, that would come from thence.
Saul died because he consulted a medium to pray to the dead.
1 Chronicles 10:13-14 ... So Saul died for his transgression which he committed against the Lord, even against the word of the Lord, which he kept not, and also for asking counsel of one that had a familiar spirit, to enquire of it; And enquired not of the Lord: therefore he slew him, and turned the kingdom unto David the son of Jesse.
Communication with dead people is absolutely condemned by the Word of God. It does not matter if those who died were good people or bad people, holy people or evil people. Communication (praying, consulting etc.) with dead people is FORBIDDEN by God.
Deuteronomy 18:9-12 ... When thou art come into the land which the Lord thy God giveth thee, thou shalt not learn to do after the abominations of those nations. There shall not be found among you any one that maketh his son or his daughter to pass through the fire, or that useth divination, or an observer of times, or an enchanter, or a witch. Or a charmer, or a consulter with familiar spirits, or a wizard, or a necromancer. For all that do these things are an abomination unto the Lord: and because of these abominations the Lord thy God doth drive them out from before thee.
Isaiah 19:3 ... And the spirit of Egypt shall fail in the midst thereof; and I will destroy the counsel thereof: and they shall seek to the idols, and to the charmers, and to them that have familiar spirits, and to the wizards.
Prayer is an act of worship. Angels are fellow-servants and they reject our worship. Thus, Angels also reject our prayers.
1 John 5:14-15 ... And this is the confidence that we have in him, that, if we ask any thing according to his will, he heareth us: And if we know that he hear us, whatsoever we ask, we know that we have the petitions that we desired of him.
Neither angels nor any other created being is ever depicted as an intercessor with God the Father. Only the Son and the Holy Spirit can intercede before the Father’s throne.
Romans 8:26 ... Likewise the Spirit also helpeth our infirmities: 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.
Hebrews 4:15-16 ... For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin. Let us therefore come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need.
1 Timothy 2:5 ... For there is one God, and one mediator between God and men, the man Christ Jesus;
When Believers pray, we pray directly to Abba Father, in Jesus name.