"When men tell you to consult mediums and spiritists, who whisper and mutter, should not a people inquire of their God? Why consult the dead on behalf of the living?" Isaiah 8:19
" 'Do not turn to mediums or seek out spiritists, for you will be defiled by them. I am the Lord your God." Leviticus 19:31
" 'I will set my face against the person who turns to mediums and spiritists to prostitute himself by following them, and I will cut him off from his people." Leviticus 20:6
"Let no one be found among you who sacrifices his son or daughter in the fire, who practices divination or sorcery, interprets omens, engages in witchcraft, or casts spells, or who is a medium or spiritist or who consults the dead. Anyone who does these things is detestable to the Lord, and because of these detestable practices the Lord your God will drive out those nations before you.You must be blameless before the LORD your God." Deuteronomy 18:10-13
"Once when we were going to the place of prayer, we were met by a slave girl who had a spirit by which she predicted the future. She earned a great deal of money for her owners by fortune-telling. This girl followed Paul and the rest of us, shouting, "These men are servants of the Most High God, who are telling you the way to be saved." She kept this up for many days. Finally Paul became so troubled that he turned around and said to the spirit, "In the name of Jesus Christ I command you to come out of her!" At that moment the spirit left her." Acts 16:16-18
"When this became known to the Jews and Greeks living in Ephesus, they were all seized with fear, and the name of the Lord Jesus was held in high honor. Many of those who believed now came and openly confessed their evil deeds. A number who had practiced sorcery brought their scrolls together and burned them publicly. When they calculated the value of the scrolls, the total came to fifty thousand drachmas. In this way the word of the Lord spread widely and grew in power." Acts 19:17-20
"The acts of the sinful nature are obvious: sexual immorality, impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God." Galatians 5:19-21
"Saul died because he was unfaithful to the Lord; he did not keep the word of the Lord and even consulted a medium for guidance, and did not inquire of the Lord. So the Lord put him to death and turned the kingdom over to David son of Jesse." 1 Chronicles 10:13-14 (You can see what he did in 1 Samuel Chapter 28:8-20 and the consequences)
Referring to King Manaseh of Judah- "He sacrificed his own son in the fire, practiced sorcery and divination, and consulted mediums and spiritists. He did much evil in the eyes of the Lord, provoking him to anger" 2 Kings 21:6
Also referring to King Manaseh- "He sacrificed his sons in the fire in the Valley of Ben Hinnom, practiced sorcery, divination and witchcraft, and consulted mediums and spiritists. He did much evil in the eyes of the Lord, provoking him to anger." 2 Chronicles 33:6
"And no wonder, for Satan himself masquerades as an angel of light. It is not surprising, then, if his servants masquerade as servants of righteousness. Their end will be what their actions deserve." 2 Corinthians 11:13-15
God tells us to test them to see if they are from him or not..."Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world. This is how you can recognize the Spirit of God: Every spirit that acknowledges that Jesus Christ has come in the flesh is from God, but every spirit that does not acknowledge Jesus is not from God. This is the spirit of the antichrist, which you have heard is coming and even now is already in the world." 1 John 4:1-6
"The Spirit (Speaking of the Holy Spirit) clearly says that in later times some will abandon the faith and follow deceiving spirits and things taught by demons. Such teachings come through hypocritical liars, whose consciences have been seared as with a hot iron." 1 Timothy 4:1-2
"But there were also false prophets among the people, just as there will be false teachers among you. They will secretly introduce destructive heresies, even denying the sovereign Lord who bought them bringing swift destruction on themselves." 2 Peter 2:1
"I am astonished that you are so quickly deserting the one who called you by the grace of Christ and are turning to a different gospel which is really no gospel at all. Evidently some people are throwing you into confusion and are trying to pervert the gospel of Christ. But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let him be eternally condemned!" Galatians 1:6-8
"Be self-controlled and alert. Your enemy the devil prowls around like a roaring lion looking for someone to devour. Resist him, standing firm in the faith, because you know that your brothers throughout the world are undergoing the same kind of sufferings." 1 Peter 5:8-9
"Put on the full armor of God so that you can take your stand against the devil's schemes. For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms." Ephesians 6:11-12
"Not everyone who says to me, 'Lord, Lord,' will enter the kingdom of heaven, but only he who does the will of my Father who is in heaven. Many will say to me on that day, 'Lord, Lord, did we not prophesy in your name, and in your name drive out demons and perform many miracles?' Then I will tell them plainly, 'I never knew you. Away from me, you evildoers!" Matthew 7:21-23
"My conscience is clear, but that does not make me innocent. It is the Lord who judges me." 1 Corinthians 4:4
"There is a way that seems right to a man, but in the end it leads to death." Proverbs 14:12
"All a man's ways seem innocent to him, but motives are weighed by the Lord." Proverbs 16:2
I hope this helps, puka :-)